PALEONTOLOGICAL RESOURCES ASSESSMENT STRATFORD RANCH RESIDENTIAL PROJECT CITY OF PERRIS RIVERSIDE COUNTY, CALIFORNIA

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1 PALEONTOLOGICAL RESOURCES ASSESSMENT CITY OF PERRIS RIVERSIDE COUNTY, CALIFORNIA July 2013

2 PALEONTOLOGICAL RESOURCES ASSESSMENT CITY OF PERRIS RIVERSIDE COUNTY, CALIFORNIA Prepared for: Stratford Ranch Investors 3649 Mission Inn Avenue Riverside, California Prepared by: Sarah Rieboldt, Ph.D. LSA Associates, Inc. 20 Executive Park, Suite 200 Irvine, California LSA Project No. SRA1301 Database Information: Type of Study: Locality Search and Survey Localities Recorded: None USGS 7.5 Quadrangle: Perris, California Acreage: ~80 acres Key Words: Holocene Alluvial Valley Deposits, Pleistocene Very Old Alluvial Fan Deposits, Paleontologically Sensitive Sediments July 2013

3 ABSTRACT LSA Associates, Inc. (LSA) conducted a paleontological resources assessment for the Stratford Ranch Residential Project (project), located in the City of Perris (City), Riverside County, California. The proposed project consists of the development of 400 residential lots and a 15-acre (ac) Stockpile Plan, all of which are within the 80 ac project area. This assessment included a locality search at the Division of Geological Sciences of the San Bernardino County Museum (SBCM), an examination of geologic maps and paleontological literature, and a field survey. An examination of geologic maps indicated that the project area is situated on surficial sediments of Early Pleistocene (2.588 million to 781,000 years ago) Very Old Alluvial Fan Deposits in the eastern portion and Holocene (11,700 years ago to the present) Young Alluvial Valley Deposits in the western portion. The Young Alluvial Valley Deposits likely represent a thin veneer over Middle to Late Pleistocene (781,000 to 11,700 years ago) Old Alluvial Fan Deposits that may be encountered as shallowly as 5 feet (ft) beneath the surface. Because the project area has been used for agricultural purposes, some portions of the project area may contain Artificial Fill, although these deposits are not mapped. The Young Alluvial Valley Deposits and Artificial Fill have Low sensitivity for paleontological resources to a depth of 5 ft below the surface, or however deep beneath the surface the Artificial Fill extends. The Young Alluvial Valley Deposits below a depth of 5 ft, as well as the Very Old Alluvial Fan Deposits have a High paleontological sensitivity. No paleontological resources were observed during the field survey, and the locality search conducted at the SBCM for LSA in November 2011 (see Results of Locality Search for explanation of older date) for the parcel of land immediately to the west of the project area indicated that there are no known paleontological resources within an approximate 1-mile radius around the current project area. However, significant paleontological resources have been recovered from Pleistocene deposits including from a locality within the Perris Valley Storm Channel; in addition, Pleistocene fossils are known from elsewhere in the Inland Empire and Southern California within sediments that are similar to those that are within the project area. LSA believes there is the potential to encounter paleontological resources during ground-disturbing activities in the eastern portion of the project area at the surface, as well as in the western portion if excavation extends below a depth of 5 ft. In order to mitigate potential adverse impacts to nonrenewable paleontological resources, as required by California Environmental Quality Act Appendix G, Public Resources Code Section , and the General Plan of the City, LSA recommends the following: 1) A paleontologist shall be hired to develop a Paleontological Resource Impact Mitigation Program (PRIMP) for this project. 2) Excavation and grading activities with a High paleontological sensitivity rating (Very Old Alluvial Fan Deposits and sediments beginning at approximately 5 feet [ft] beneath areas mapped as Young Alluvial Valley Deposits) shall be monitored by a qualified paleontologist following a PRIMP. 3) If any fossil remains are discovered in sediments with a Low paleontological sensitivity rating (areas mapped as Young Alluvial Valley Deposits from the surface to a depth of 5 ft), the paleontologist shall make recommendations as to whether monitoring shall be required in these sediments on a full-time basis beginning at a shallower depth. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» i

4 TABLE OF CONTENTS EXECUTIVE SUMMARY... i INTRODUCTION... 1 PROJECT LOCATION... 1 PROJECT DESCRIPTION... 1 LEGISLATION... 3 STATE REGULATIONS... 3 County of Riverside... 3 City of Perris... 4 SIGNIFICANCE AND SENSITIVITY... 5 SIGNIFICANCE... 5 Summary of Significance... 6 SENSITIVITY... 7 Summary of Sensitivity... 8 METHODS... 9 LOCALITY SEARCH... 9 FIELD SURVEY... 9 PROJECT PERSONNEL... 9 Sarah Rieboldt, Ph.D., Paleontologist... 9 Riordan Goodwin, Senior Cultural Resources Manager RESULTS GEOLOGY Artificial Fill Young Alluvial Valley Deposits (Qyv) Old Alluvial Fan Deposits Very Old Alluvial Fan Deposits (Qvof) PALEONTOLOGY Artificial Fill Young Alluvial Valley Deposits Old Alluvial Fan Deposits Very Old Alluvial Fan Deposits LOCALITY SEARCH FIELD SURVEY SUMMARY RECOMMENDATIONS REFERENCES P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» i

5 APPENDIX A: LOCALITY SEARCH RESULTS SAN BERNARDINO COUNTY MUSEUM (TO BE PROVIDED) FIGURES Figure 1: Project Vicinity and Location Map... 2 Figure 2: Geologic Map TABLE Table A: Geologic Units Within the Project Area P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» ii

6 INTRODUCTION LSA Associates, Inc. (LSA) was retained by the Stratford Ranch Investors to prepare a paleontological resources assessment for the Stratford Ranch Residential Project (project). This assessment documents the potential for paleontological resources to occur within the project area and whether those resources will be affected by development of the project. The assessment was conducted pursuant to Appendix G of the California Environmental Quality Act (CEQA) Guidelines; the California Public Resources Code (PRC) Section ; the Riverside County (County) General Plan (Riverside County, 2003), and the Conservation Element of the City of Perris (City) Comprehensive General Plan (City of Perris, 2005). This assessment also followed guidelines established by the Society of Vertebrate Paleontology (SVP, 1995, 2010). According to these regulations and guidelines, if development of a project impacts significant paleontological resources, a plan must be developed and to mitigate those impacts. PROJECT LOCATION The proposed project covers an 80-acre (ac) rectangular parcel of land located north of the Ramona Expressway roughly between the Perris Valley Storm Drain on the west and Evans Road on the east within the City of Perris, Riverside County, California. The project area is depicted on the United States Geological Survey (USGS) Perris, California 7.5-minute topographic quadrangle (1967, photorevised 1979) in the eastern portion of Section 5; Township 4 South; Range 3 West, San Bernardino Baseline and Meridian (Figure 1). PROJECT DESCRIPTION The Stratford Ranch Investors propose to develop a residential community that consists of 400 residential lots and a 15 ac Stockpile Plan within an 80 ac area. The project will include clearing and grading to prepare the project area, construction of a new road within the area, and installation of onsite storm drains, new water service, new sewer lines, new electric service, new natural gas lines, and new telecommunications infrastructure systems to serve the proposed residential uses. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 1

7 San Bernardino County à Project Vicinity à 38 à 60 à Riverside County Project Location à 79 à LEGEND FIGURE 1 Project Location FEET SOURCE: USGS 7.5' QUAD - PERRIS ('79) I:\SRA1301\GIS\Project_Location.mxd (6/7/2013) Stratford Ranch Residential Project Vicinity and Location Map

8 LEGISLATION STATE REGULATIONS Under State law, paleontological resources are protected by CEQA and PRC Section Under CEQA, Lead Agencies are required to consider impacts related to the direct or indirect destruction of unique resources that are of value to the region or State. Appendix G of the CEQA Guidelines is a checklist with several choices given, including Potentially Significant Impact, Less than Significant with Mitigation Incorporation, Less than Significant Impact, and No Impact. Specifically, in Appendix G, Section V(c), Lead Agencies are required to consider impacts to paleontological resources. The California PRC Section states: (a) No person shall knowingly and willfully excavate upon, or remove, destroy, injure or deface any historic or prehistoric ruins, burial grounds, archaeological or vertebrate paleontological site, including fossilized footprints, inscriptions made by human agency, or any other archaeological, paleontological or historical feature, situated on public lands, except with the express permission of the public agency having jurisdiction over such lands. Violation of this section is a misdemeanor. (b) As used in this section, public lands means lands owned by, or under the jurisdiction of, the state, or any city, county, district, authority, or public corporation, or any agency thereof. Consequently, the County and the City are required to comply with PRC Section County of Riverside The County General Plan (Riverside County, 2003) sets forth the goals, policies, and programs the County uses to manage future growth and land uses. Although the General Plan usually only applies to portions of the County that are unincorporated, this section is being included for completeness. Chapter 5 the Multipurpose Open Space Element of the General Plan contains the policies designed to protect paleontological resources within unincorporated areas of the County. The following policies contained in the General Plan of the County are designed to protect paleontological resources within the County. OS Whenever existing information indicates that a site proposed for development may contain biological, paleontological, or other scientific resources, a report shall be filed stating the extent and potential significance of the resources that may exist within the proposed development and appropriate measures through which the impacts of development may be mitigated. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 3

9 OS This policy requires that when existing information indicates that a site proposed for development may contain paleontological resources, a paleontologist shall monitor site grading activities, with the authority to halt grading to collect uncovered paleontological resources, curate any resources collected with an appropriate repository, and file a report with the Planning Department documenting any paleontological resources that are found during the course of site grading. OS Transmit significant development applications subject to CEQA to the San Bernardino County Museum for review, comment, and/or preparation of recommended conditions of approval with regard to paleontological resources. City of Perris The Conservation Element of the City s Comprehensive General Plan (2030) (City of Perris, 2005) states that identification and preservation of significant fossils will be effected through Implementation Measure IV.A.4. Measure IV.A.4: In Area 1 and Area 2 shown on the Paleontological Sensitivity Map, paleontologic monitoring of all projects requiring subsurface excavations will be required once any excavation begins. In Areas 4 and 5, paleontologic monitoring will be required once subsurface excavations reach five feet in depth, with monitoring levels reduced if appropriate, at the discretion of a certified Project Paleontologist. Based on the Paleontological Sensitivity Map in the Conservation Element of the City s Comprehensive General Plan (2030) (City of Perris 2005, Exhibit CN-7), the project is located within Area 4, which requires paleontological monitoring beginning at a depth of 5 ft beneath the surface. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 4

10 SIGNIFICANCE AND SENSITIVITY Paleontological resources, or fossils, are the remains (such as bones, teeth, shells, leaves, or wood) and/or traces (such as tracks or burrows) of prehistoric animal and plant life. Fossils provide evidence of ancient organisms and can document the patterns of organic evolution and extinction. According to the SVP (2010), paleontological resources differ from archaeological resources in that archaeological resources are human remains and items, artifacts, and ecofacts associated with human cultures. If paleontological resources are determined to be in close stratigraphic association with human remains or humanmade items, or if fossils can be demonstrated to be intentionally modified by humans, they are also considered archaeological resources and will be treated as such. This will generally not be an issue except on very old sites that span the Holocene-Pleistocene boundary, approximately 11,700 years ago. SIGNIFICANCE The SVP provides the following definitions of significance. Significant Paleontological Resources are fossils and fossiliferous deposits, here defined as consisting of identifiable vertebrate fossils, large or small; uncommon invertebrate, plant, and trace fossils; and other data that provide taphonomic, taxonomic, phylogenetic, paleoecologic, stratigraphic, and/or biochronologic information. Paleontological resources are considered to be older than recorded human history and/or older than middle Holocene (i.e., older than approximately 5,000 radiocarbon years) (SVP, 2010). A Significant Fossiliferous Deposit is a rock unit or formation that contains significant nonrenewable paleontological resources, here defined as comprising one or more identifiable vertebrate fossils, large or small; and any associated invertebrate and plant fossils, traces, and other data that provide taphonomic, taxonomic, phylogenetic, ecologic, and stratigraphic information (ichnites and trace fossils generated by vertebrate animals, e.g., trackways or nests and middens, which provide datable material and climatic information). Paleontological resources are considered to be older than recorded history and/or older than 5,000 years before the present (SVP, 1995). Generally, scientifically significant paleontological resources are identified sites or geological deposits containing individual fossils or assemblages of fossils that are unique or unusual, diagnostically or stratigraphically important, and add to the existing body of knowledge in specific areas, stratigraphically, taxonomically, or regionally (SVP, 1995). Particularly important are fossils found in situ (undisturbed) in primary context (e.g., fossils that have not been subjected to disturbance subsequent to their burial and fossilization). As such, they aid in stratigraphic correlation, particularly those offering data for the interpretation of tectonic events, geomorphologic evolution, paleoclimatology, the relationships between aquatic and terrestrial species, and evolution in general. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 5

11 Discovery of in situ fossil-bearing deposits is rare for many species, especially vertebrates. Terrestrial vertebrate fossils are often assigned greater significance than other fossils because they are rarer than other types of fossils. This is primarily because the best conditions for fossil preservation include little or no disturbance after death and quick burial in oxygen-depleted, fine-grained, sediments. While these conditions often exist in marine settings, they are relatively rare in terrestrial settings. This has ramifications with regard to the amount of scientific study needed to characterize an individual species adequately and therefore affects how relative sensitivities are assigned to formations and rock units. Eisentraut and Cooper (2002) developed a useful analysis for judging whether fossils are scientifically significant by applying the criteria within the following categories: Taxonomy: Assemblages that contain rare or unknown taxa, such as defining new (previously unknown to science) species or that represent a species that is the first or has very limited occurrence within the area or formation. Evolution: Fossils that represent important stages or links in evolutionary relationships or that fill gaps or enhance underrepresented intervals in the stratigraphic record. Biostratigraphy: Fossils that are important for determining or confining relative geologic (stratigraphic) ages or for use in defining regional to interregional stratigraphic associations. These fossils are often known as biostratigraphic markers and represent plants or animals that existed for only a short and restricted period in the geologic past. Paleoecology: Fossils that are important for reconstructing ancient organism community structure and interpretation of ancient sedimentary environments. Depending on which fossils are found, much can be learned about the ancient environment from water depth, temperature, and salinity to what the substrate was like (muddy, sandy, or rocky) to even whether the area was in a high energy location like a beach or low-energy location like a bay. Even terrestrial animals can contain information about the ancient environment. For example, an abundance of grazing animals such as horses, bison, and mammoths suggest more of a grassland environment, while an abundance of browsing animals such as deer, mastodons, and camels suggest more of a brushy environment. Preserved parts of plants can also lend insight into what was growing in the area at a particular time. In addition, by studying the ratios of different species to each other s population densities, relationships between predator and prey can be determined. There is a complex but vital interrelationship among evolution, biostratigraphy, and paleoecology: biostratigraphy (the record of fossil succession and progression) is the expression of evolution (change in populations of organisms through time), which in turn is driven by natural selection pressures exerted by changing environments (paleoecology). Taphonomy: Fossils that are exceptionally well or unusually/uniquely preserved or are relatively rare in the fossil record. This could include preservation of soft tissues such as hair, skin, or feathers from animals or the leaves/stems of plants that are not commonly fossilized. Summary of Significance All vertebrate fossils that are in stratigraphic context are scientifically significant and are considered a scientifically significant nonrenewable paleontological resource. Invertebrate and plant fossils, as P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 6

12 well as other environmental indicators, associated with vertebrate fossils are considered scientifically significant. Certain invertebrate and plant fossils that are regionally rare or uncommon, or help to define stratigraphy, age, or taxonomic relationships, are also considered scientifically significant. SENSITIVITY Paleontological sensitivity refers to the potential to encounter significant paleontological resources in a given geologic unit. Decisions about how to manage paleontological resources must be based on the potential to encounter those resources as the actual situation cannot be known until excavation for the project is underway. All sedimentary rocks, some volcanic rocks, and some metamorphic rocks have potential for the presence of significant nonrenewable paleontological resources. Review of available literature may further refine the potential of each rock unit, formation, or facies. The SVP (2010) has four categories for sensitivity: High, Low, No, and Undetermined; while the City Planning Department (City of Perris, 2005) has only three categories of sensitivity: High, Low, and Undetermined. If a geographic area or geological unit is classified as having Undetermined Potential for paleontological resources, studies must be undertaken to determine whether that rock unit has a sensitivity of either High or Low. The field survey may extend outside the defined project to areas where rock units are better exposed. The categories of paleontological potential are defined below: High Potential: Rock units from which vertebrate or significant invertebrate, plant, or trace fossils have been recovered are considered to have a High Potential for containing additional significant paleontological resources. Rock units classified as having High Potential for producing paleontological resources include, but are not limited to, sedimentary formations and some volcaniclastic formations (e.g., ashes or tephras), some low-grade metamorphic rocks that contain significant paleontological resources anywhere within their geographical extent, and sedimentary rock units temporally or lithologically suitable for the preservation of fossils (e.g., middle Holocene and older, fine-grained fluvial sandstones, argillaceous and carbonate-rich paleosols, cross-bedded point bar sandstones, fine-grained marine sandstones). Paleontological potential consists of both (1) the potential for yielding abundant or significant vertebrate fossils or for yielding a few significant fossils, large or small, vertebrate, invertebrate, plant, or trace fossils, and (2) the importance of recovered evidence for new and significant taxonomic, phylogenetic, paleoecologic, taphonomic, biochronologic, or stratigraphic data. Rock units that contain potentially datable organic remains older than late Holocene, including deposits associated with animal nests or middens, and rock units which may contain new vertebrate deposits, traces, or trackways, are also classified as having High Potential. Low Potential: Reports in the paleontological literature or field surveys by a qualified professional paleontologist may allow determination that some rock units have a Low Potential for yielding significant fossils. Such rock units will be poorly represented by fossil specimens in institutional collections, or based on general scientific consensus, fossils are only preserved in rare circumstances; the presence of fossils is the exception, not the rule (e.g., basalt flows or Recent colluvium). Rock units with Low Potential typically will not require impact mitigation measures to protect fossils. No Potential: Some rock units have No Potential to contain significant paleontological resources (e.g., high-grade metamorphic rocks [such as gneisses and schists] and plutonic igneous rocks [such as granites and diorites]). Rock units with No Potential require no protection or impact mitigation measures relative to paleontological resources. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 7

13 Undetermined Potential: Rock units for which little information is available concerning their paleontological content, geologic age, and depositional environment are considered to have Undetermined Potential. Further study is necessary to determine whether these rock units have High, Low, or No Potential to contain significant paleontological resources. A field survey by a qualified professional to specifically determine the paleontological resource Potential of these rock units is required before a Paleontological Resource Impact Mitigation Program (PRIMP) can be developed. In cases where no subsurface data are available, paleontological potential can sometimes be determined by strategically located excavations into subsurface stratigraphy. If an area is determined to have a High Potential for containing paleontological resources, the SVP (2010) recommends that a program to mitigate impacts be developed. In areas of High Sensitivity, a survey prior to excavation is also recommended to locate surface concentrations of fossils that might need special salvage methods. Mitigation can be initiated prior to and/or during construction. As a practical matter, no consideration is generally afforded paleontological sites for which scientific importance cannot be demonstrated. If a paleontological resource assessment determines an area is insignificant or of Low sensitivity, it is recommended that this conclusion be documented in the assessment report and in the project s environmental document in order to demonstrate compliance with applicable statutory requirements. Summary of Sensitivity A formation or rock unit has paleontological sensitivity or the potential for significant paleontological resources if it has previously produced, or has lithologies conducive to the preservation of, vertebrate fossils and associated or regionally uncommon invertebrate and plant fossils. All sedimentary rocks, except those younger than 11,700 years, certain extrusive volcanic rocks, and mildly metamorphosed rocks are considered to have potential for paleontological resources. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 8

14 METHODS LOCALITY SEARCH A paleontological locality search was conducted through the SBCM and geological and paleontological records maintained at LSA. The search included a review of the area geology and any known paleontological resources recovered from the surrounding area, as well as the geologic units that will likely be encountered during excavation activities associated with the project. As geologic formations and units may extend over large geographic areas and contain similar lithologies and fossils, the literature review and fossil locality search includes areas well beyond the project area. LSA also reviewed the paleontological resources assessment that was prepared for the North Perris Industrial Specific Plan (Quinn, 2007). The purpose of the locality search was to establish the status and extent of previously recorded paleontological resources within and adjacent to the project. With this knowledge, LSA could make an informed assessment of the potential effects of the proposed project on paleontological resources and evaluate the types of fossils that might be uncovered during ground-disturbing activities. In addition, the sensitivity of the sediments expected to be encountered within the project could be determined. FIELD SURVEY On June 21, 24, and 25, 2013, LSA Personnel Riordan Goodwin conducted a pedestrian survey of the entire 80 ac project area. All portions of the property were surveyed in systematic parallel transects spaced by approximately 15 meters (50 ft). Special attention was paid to areas of exposed sediment such as graded cuts, as well as rodent burrows, that help to expose subsurface conditions. The purpose of this survey was to confirm the accuracy of the geologic mapping and to identify whether any paleontological resources might be exposed on the surface. In this way, LSA could document the existence of paleontological material prior to the beginning of ground-disturbing activities and locate areas within the project that might contain abundant remains. PROJECT PERSONNEL Sarah Rieboldt, Ph.D., Paleontologist Dr. Rieboldt received her Ph.D. in Paleontology from the University of California, Berkeley and has extensive experience surveying for and collecting paleontological resources; salvaging large fossil specimens; collecting bulk sediment samples; identifying, preparing, and curating fossil material; and writing paleontological assessment reports and final mitigation monitoring reports at the conclusion of construction projects. She has conducted paleontological and geological fieldwork in California, Nevada, Utah, Wyoming, Colorado, and Alabama and has five years of experience working with natural history collections in several museums (Field Museum of Natural History [Chicago], P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 9

15 University of California Museum of Paleontology, and University of Colorado Museum of Natural History). As a geologist and paleontological consultant, Dr. Rieboldt has worked on many different projects, including carbon sequestration and astrobiology research programs funded by the United States Department of Energy (DOE) and National Aeronautic and Space Administration (NASA), respectively, as well as on projects for the State of California Department of Parks and Recreation (DPR), the California Department of Transportation (Caltrans), and various private developers in California, Nevada, and Utah. Riordan Goodwin, Senior Cultural Resources Manager Riordan Goodwin conducted the paleontological survey for this project. Mr. Goodwin is quite familiar with the project vicinity, having conducted the survey and archaeological testing on the adjacent Stratford Ranch Industrial project, as well as the Pelican Properties project located a short distance to the west. He has more than 20 years of paleontological and archaeological experience in Southern and Central California and has served as Field Supervisor/Coordinator, Lead Monitor, and/ or Monitor on numerous projects. Mr. Goodwin is currently the laboratory manager in LSA s Riverside office. Since joining LSA, Mr. Goodwin has personally conducted and contributed to numerous Phase I and Phase II assessments at the CEQA-level and National Environmental Protection Act (NEPA) level, and evaluations for projects varying in size from less than 1 ac to tracts as large as 20,000 ac, as well as expansive transportation improvements for paleontological and cultural resources. Surveys usually involve Global Positioning System (GPS) mapping, site and locality descriptions, and/or recordation, and occasionally have required limited surface collections. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 10

16 RESULTS GEOLOGY The project area is located at the northern end of the Peninsular Ranges Geomorphic Province, a 900- mile long northwest-southeast trending structural block that extends from the Transverse Ranges to the tip of Baja California and includes the Los Angeles Basin (California Geological Survey, 2002; Norris and Webb, 1976). The total width of this province is approximately 225 miles, extending from the Colorado Desert in the east, across the continental shelf to the Southern Channel Islands (Santa Barbara, San Nicolas, Santa Catalina, and San Clemente) in the west. This region is characterized by a series of mountain ranges separated by northwest-trending valleys subparallel to faults branching from the San Andreas Fault. The geology of this province is similar to that of the Sierra Nevada, with granitic rock intruding into the older metamorphic rocks. It contains extensive pre-cretaceous (> 65 million years ago) igneous and metamorphic rocks covered by limited exposures of post- Cretaceous sedimentary deposits. Within this province, the project is located on the Perris Block, a fault-bounded structural block that extends from the southern foot of the San Gabriel and San Bernardino Mountains southeast to the vicinity of Bachelor Mountain and Polly Butte (Morton and Miller, 2006; Kenney, 1999). It is bounded on the northeast by the San Jacinto Fault and on the southwest by the Elsinore Fault Zone (Morton and Miller, 2006). Prior to the Late Pleistocene (~126,000 years ago), the Perris Block was tectonically tilted eastward, elevating and exposing older granitic rocks on the west side (Jurupa Hills) and allowing Pleistocene sediments to accumulate on the east side, filling the eastern San Bernardino, Lakeview, Perris, and San Jacinto Valleys. The Perris Valley Storm Channel (PVSC), located approximately 200 ft west of the project s western boundary, roughly follows the central path of the Perris Valley and connects to the San Jacinto River, a major river that drains the Perris Block, approximately 5.5 miles south of the project area. Within the surface of the project area, Morton (2003) and Morton and Miller (2006) mapped Holocene (11,700 years ago to the present) Young Alluvial Valley Deposits and Early to Middle Pleistocene (2.588 million to 781,000 years ago) Very Old Alluvial Fan Deposits. It is likely that Middle to Late Pleistocene (781,000 to 11,700 years ago) Old Alluvial Fan Deposits are present below the surface where Young Alluvial Valley Deposits are mapped. In addition, because the project area was previously developed for agricultural purposes, some portions may contain Artificial Fill; however, these deposits were not mapped by Morton (2003) or Morton and Miller (2006) and their thickness is not known. Figure 2 depicts the geologic units mapped at the surface within the project area. All of the geologic units that may be encountered are described in more detail below and summarized in Table A. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 11

17 Qyv Qvof Qvof LEGEND FIGURE 2 Project Location Geology FEET SOURCE: USGS 7.5' QUAD - PERRIS ('79); Morton (2003) I:\SRA1301\GIS\Geology.mxd (6/7/2013) (Qyv) Young Alluvial Valley Deposits (Qvof) Very Old Alluvial Fan Deposits (Khg) Heterogeneous Granitic Rocks Stratford Ranch Residential Geologic Map

18 Table A: Geologic Units Within the Project Area Map Symbol Geologic Unit Epoch Age (years) 1 N/A Artificial Fill Holocene Less than 100 Young Alluvial Valley Qyv Holocene Less than 11,700 Deposits N/A Old Alluvial Fan Deposits Middle to Late Pleistocene 781,000 11,700 Very Old Alluvial Fan Qvof Early to Middle Pleistocene Deposits 1 Source: International Commission on Stratigraphy (2013) N/A = Not Applicable million 781,000 Artificial Fill Artificial Fill consists of sediments that have been removed from one location and transported to another location by human activity, rather than by natural means. The transportation distance can vary from a few feet to many miles. Composition is dependent on the source. When it is compacted and dense, it is known as engineered fill, but it can be loosely compacted. Artificial Fill will sometimes contain modern debris such as asphalt, wood, bricks, concrete, metal, glass, plastic, and even plant material. Young Alluvial Valley Deposits (Qyv) Young Alluvial Valley Deposits are generally found in valley floors and represent deposition by small streams flowing from the mountains and into the central portion of a valley. They often represent deposition during flood events. These deposits are mapped on the surface in the western portion of the project area and consist of unconsolidated sand and silt that accumulated during the Holocene (11,700 years ago to the present) (Morton, 2003; Morton and Miller, 2006). Colors are variable and based on upstream geology, but are usually shades of gray to yellow brown. Old Alluvial Fan Deposits Old Alluvial Fan Deposits formed during the Middle to Late Pleistocene (781,000 to 11,700 years ago) (Morton, 2003; Morton and Miller, 2006) from sediments that eroded from the mountains were carried to lower elevations by rivers and streams. They are found at the mouths of canyons, along the sides of hills that flank river and stream valleys, and within the valleys themselves. These deposits are composed slightly to well consolidated mixtures of sand, cobbles, and silt. They have been dissected by erosional gullies and show some soil development. Colors are variable and based on upstream geology, but are usually shades of reddish brown. Although not exposed at the surface within the project area, these deposits may exist at depth below the Young Alluvial Valley Deposits beginning as shallowly as 5 ft beneath the surface. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 13

19 Very Old Alluvial Fan Deposits (Qvof) The Very Old Alluvial Fan Deposits formed during the Early to middle Pleistocene (2.588 million to 781,000 years ago) (Morton, 2003; Morton and Miller, 2006) from sediment carried by rivers and streams down the mountains and deposited at the mouths of canyons, along the sides of hills flanking river and stream valleys, and within the valleys themselves. These deposits consist of a mixture of sand, cobbles, and silt. They are slightly to well consolidated, and in some areas have been dissected by erosional gullies, and when not disturbed by agricultural activities show some soil development. Colors are variable and based on upstream geology, but are usually shades of reddish brown. These deposits are exposed on the surface in the eastern portion of the project area and like the Old Alluvial Fan Deposits described above, may exist at depth below the Young Alluvial Valley Deposits beginning as shallowly as 5 ft beneath the surface. PALEONTOLOGY Artificial Fill Artificial Fill may contain fossils, but these fossils have been removed from their original location and are thus out of stratigraphic context. They are not considered significant under CEQA or by the SVP (1995, 2010), and are not important for scientific study. However, Middle to Late Pleistocene Old Alluvial Fan deposits, which may contain significant fossil resources, may be encountered beneath these deposits, as shallowly as 5 ft below the surface. For these reasons, Artificial Fill is assigned a Low paleontological sensitivity rating. Young Alluvial Valley Deposits The Young Alluvial Valley Deposits within the project area were deposited during the Holocene (11,700 years ago to the present). Although Holocene-age deposits may contain remains of plants and animals, generally not enough time has passed for the remains to become fossilized, except for those sediments at the older end of the Holocene. In addition, except for the early Holocene (approximately 11,700 to 10,000 years ago), the remains are contemporaneous with modern species, and therefore, are usually not considered to be scientifically significant. However, Middle to Late Pleistocene Old Alluvial Fan deposits, which may contain significant fossil resources, may be encountered beneath these deposits, as shallowly as 5 ft below the surface. For these reasons, the Young Alluvial Valley Deposits are assigned a Low paleontological sensitivity rating. Old Alluvial Fan Deposits The Old Alluvial Fan Deposits accumulated during the Middle to Late Pleistocene (781,000 to 11,700 years ago) and may be encountered within the project area beneath the Young Alluvial Valley Deposits, possibly as shallow as 5 ft below the surface. These deposits span the latest two North American Land Mammal Ages (NALMAs): the Irvingtonian (1.8 million to 240,000 years ago) and the Rancholabrean (240,000 to 11,700 years ago). Fossils are known in similar Irvingtonian and Rancholabrean deposits from excavations for roads, housing developments, and quarries, as well as scientific investigations within the Southern California area (Jefferson, 1991a, 1991b; Miller, 1971; Pajak et al., 1996; Reynolds and Reynolds, 1991; Springer et al., 2009). These fossils include mammoths, mastodons, horses, bison, camels, saber-toothed cats, coyotes, deer, and sloths, as well as P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 14

20 smaller animals like rodents, rabbits, birds, reptiles, and fish. In addition, an article in the Riverside County Press-Enterprise newspaper reported mastodon, bison, and turtle fossils from Late Pleistocene deposits within the PVSC (McKinnon, 2009). As such, these deposits are considered to have a High paleontological sensitivity. Very Old Alluvial Fan Deposits The Very Old Alluvial Fan Deposits formed during the Early Pleistocene (2.588 million to 781,000 years ago), an interval that spans two NALMAs: the Blancan (4.75 to 1.8 million years ago) and the Irvingtonian (1.8 million to 240,000 years ago). Fossils are known in similar Blancan and Irvingtonian deposits from excavations for roads, housing developments, and quarries, as well as scientific investigations within the Southern California area (Jefferson, 1991a, 1991b; Miller, 1971; Pajak et al., 1996; Reynolds and Reynolds, 1991; Springer et al. 2009). These fossils include mammoths, mastodons, horses, camels, saber-toothed cats, coyotes, deer, peccaries, and sloths, as well as smaller animals like rodents, rabbits, birds, reptiles, and fish. As such, these deposits are considered to have a High paleontological sensitivity. LOCALITY SEARCH A locality search request was made to the SBCM on June 7, As of June 27, 2013, LSA had not received any results. A call was placed to the SBCM on the same day and LSA was informed that the museum curator was out until at least July 5, As such, LSA is utilizing the results for a locality search conducted for the Stratford Ranch Industrial Project, which is located immediately to the west of the Stratford Ranch Residential project, as the results and recommendations will likely be similar. If and when the actual results are obtained, and if they are substantially different, an addendum letter will be prepared. This locality search letter only discusses Pleistocene deposits as being within the subsurface because there are no exposures of this age within the Stratford Ranch Industrial project. However, the conclusions and recommendations made by the SBCM for subsurface Pleistocene deposits would also apply to the Pleistocene deposits found at the surface in the eastern portion of the current project area. According to the locality search letter from the SBCM, dated November 22, 2011 (Appendix A), the SBCM examined the Regional Paleontologic Locality Inventory (RPLI) and does not have any recorded paleontological localities within the project area or within a 1-mile radius of the project area. The SBCM indicates that the Holocene Alluvial Valley Deposits exposed on the surface are too young to have a potential for containing paleontological resources. However, The SBCM states that the early to middle Pleistocene alluvium present within the subsurface of the project has a High Potential to contain nonrenewable paleontological resources and is assigned a High paleontological sensitivity. The SBCM indicates that similar older Pleistocene deposits have yielded significant fossils of plants and extinct animals from the Ice Age. These finds include mammoths, mastodons, ground sloths, dire wolves, short faced bears, saber-toothed cats, large and small horses, large and small camels, and bison. However, the SBCM did not indicate how deeply beneath the surface these Pleistocene sediments may begin to be encountered. Based on geologic mapping for the current project, it is known that these older sediments are exposed on the surface within the eastern portion of the project. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 15

21 Based on the High paleontological sensitivity of sediments located in the subsurface of the project, the SBCM recommends that a qualified vertebrate paleontologist be retained to develop a program to mitigate impacts to paleontological resources. The mitigation program should be consistent with provisions of CEQA, any County regulations that apply, and guidelines of the SVP. The program should include monitoring within areas likely to contain paleontological resources, preparation of collected specimens to a point of identification, curation of any recovered resources into an accredited museum repository such as the SBCM, and preparation of a report of findings with an itemized inventory of collected specimens. FIELD SURVEY No paleontological resources were observed during the field survey. Ground visibility at the time of the survey was generally fair to poor averaging around 50 percent over most areas. Visibility was limited by a thick growth of vegetation (Russian Thistle and other species) up to 5 ft in height and remnant (abandoned) grain crops. Soil stock-piling obscured a small fraction of the project area and extensive modern dumping was noted on the periphery of the project. Two retention basins that have been excavated within the project expose some of the deeper sediments within the project area. These extend to depths of approximately 6 7 ft below the surrounding ground surface. Sediments exposed within the project area consisted of yellowish-gray to reddish-brown silty-sand to sandy silt. The sediments exposed on the surface of the most of the project area are consistent with Holocene Alluvium and Pleistocene Alluvium with the Holocene Alluvium that have been mapped within the project area. The Holocene Alluvium is somewhat lighter in color and the Pleistocene Alluvium is somewhat more reddish. SUMMARY The results of the locality search and the field survey indicate that there are no known paleontological resources within the project area or within a 1-mile radius around the project. However, significant paleontological resources have been recovered elsewhere in the Inland Empire and Southern California from Early to Late Pleistocene deposits similar to those at the surface and in the subsurface within the project area. The Holocene Young Alluvial Valley Deposits in the western portion of the project area, as well as the Artificial Fill that may be found throughout the project area, have a Low paleontological sensitivity to a depth of 5 ft below the surface. Where these deposits are mapped below a depth of 5 ft, Late Pleistocene Alluvial Valley and Old Alluvial Fan Deposits, which have High paleontological sensitivity, may be encountered. In the eastern portion of the project area, Very Old Alluvial Fan Deposits (Early to Middle Pleistocene [2.588 million to 11,700 years ago]), which also have a High paleontological sensitivity rating, are mapped at the surface. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 16

22 RECOMMENDATIONS Although no significant paleontological resources were identified directly within the project area during the locality search or field survey, the results of the locality search and examination of geologic maps and relevant literature indicate that the project area encompasses deposits of High paleontological sensitivity. These deposits include the Early Pleistocene Very Old Alluvial Fan Deposits mapped at the surface in the eastern portion of the project area and the Old Alluvial Fan Deposits, which may be reached 5 ft beneath the surface where Young Alluvial Valley Deposits are mapped in the western portion. Therefore, there is the potential to encounter paleontological resources during ground-disturbing activities in the eastern portion of the project area at the surface, as well as in the western portion if excavation extends below this 5-foot depth. In order to mitigate potential adverse impacts to nonrenewable paleontological resources, as required by CEQA Appendix G, PRC Section , and the General Plan of the City, LSA recommends the following procedures: A paleontologist shall be hired to develop a Paleontological Resource Impact Mitigation Program (PRIMP) for this project. The PRIMP shall include the methods that will be used to protect paleontological resources that may exist within the project area, as well as procedures for monitoring, fossil preparation and identification, curation into a repository, and preparation of a report at the conclusion of grading. Excavation and grading activities with a High paleontological sensitivity rating (Very Old Alluvial Fan Deposits and Young Alluvial Valley Deposits and Artificial Fill below a depth of 5 feet [ft] from the surface) shall be monitored by a qualified paleontologist following a PRIMP. If paleontological resources are encountered during the course of ground disturbance, the paleontological monitor shall have the authority to temporarily redirect construction away from the area of the find in order to assess its significance. Collected resources shall be prepared to the point of identification, identified to the lowest taxonomic level possible, cataloged, and curated into the permanent collections of an accredited scientific institution. At the conclusion of the monitoring program, a report of findings shall be prepared to document the results of the monitoring program. In the event that paleontological resources are encountered when a paleontological monitor is not present, work in the immediate area of the find shall be redirected and a paleontologist should be contacted to assess the find for significance; if determined to be significant, the fossil shall be collected from the field. In addition, if the find is located in sediments with a Low paleontological sensitivity rating (Young Alluvial Valley Deposits to a depth of 5 ft below the surface), the paleontologist shall make recommendations as to whether monitoring shall be required in these sediments on a full-time basis beginning at a shallower depth. By following the above procedures, potential impacts to nonrenewable paleontological resources would be avoided. P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 17

23 REFERENCES California Geological Survey 2002 California Geomorphic Provinces. California Geologic Survey Note 36. California Department of Conservation. Eisentraut, P., and J. Cooper 2002 Development of a Model Curation Program for Orange County s Archaeological and Paleontological Collections. Prepared by California State University, Fullerton and submitted to the County of Orange PFRD/HPB. International Commission on Stratigraphy 2013 International Stratigraphic Chart. Published by the International Commission on Stratigraphy. January Available online at Jefferson, George T. 1991a A Catalogue of Late Quaternary Vertebrates from California: Part One: Non-marine Lower Vertebrate and Avian Taxa. Natural History Museum of Los Angeles County Technical Reports Number 5, Los Angeles. 1991b A Catalogue of Late Quaternary Vertebrates from California: Part Two: Mammals. Natural History Museum of Los Angeles County Technical Reports Number 7, Los Angeles. Kenney, Miles D Emplacement, Offset History, and Recent Uplift of Basement within the San Andreas Fault System, Northeastern San Gabriel Mountains; University of Oregon. McKinnon, Julissa 2009 Paleontologists Carefully Dig Out Ancient Finds in Perris. The Press-Enterprise online edition (PE.com), January 27, 2009, Riverside, California. Miller, W.E Pleistocene Vertebrates of the Los Angeles Basin and Vicinity (Exclusive of Rancho La Brea). Los Angeles County Museum of Natural History Bulletin, Science: No. 10. Morton, Douglas M Preliminary Geologic Map of the Perris 7.5' Quadrangle, Riverside County, California, Version 1.0. Map Scale 1:24,000. Digital preparation by Kelly R. Bovard and Rachael M. Alvarez. U.S. Geological Survey Prepared in Cooperation with the Eastern Municipal Water District and the California Division of Mines and Geology. Open-File Report P:\SRA1301\Paleo\Stratford Ranch Residential Project Paleo Assessment.doc «07/03/13» 18