This data set represents the digital range map of Joshua Tree ( Yucca brevifolia ) in western North America. It is only found in the Southern California Region of California.

We delineated the existing empirical ranges of western and eastern Joshua trees (Yucca brevifolia and Y. jaegeriana, respectively) with high fidelity across their ranges in Arizona, California, Nevada, and Utah, USA. Most species distribution models (SDMs) rely on sparse species occurrence datasets and random pseudoabsences. In contrast, the tall stature and distinctive branching arms of Joshua trees enabled us to definitively identify this species in publicly available satellite imagery, allowing us to use intensive visual grid searches to map empirical presences and absences at a 0.25 km2 resolution across most of the species’ ranges. We used the resulting presence/absence data to train species distribution models (SDMs) for each Joshua tree species, as well as a rangewide model comprising the distribution data from both species. Species distribution models link species' presence / absence data with environmental characteristics including topography, climate, and soils, revealing the contemporary environmental gradients (during the past 40 years) with greatest influence on the current habitat of adult trees. Each SDM in this data release consists of a GeoTiff raster file giving the probability of occurrence for one or both species of Joshua tree, with values ranging from 0 (very low probability of species occurrence) to 1 (very high probability of species occurrence). SDM raster layers are named according to the species they represent.

Joshua tree is a visually distinctive plant found in California''s Mojave Desert and adjacent areas. The unique silhouette and tall stature of Joshua tree relative to typical surrounding vegetation make it one of the most recognizable native plants of California deserts. There are two species of Joshua tree in California, western Joshua Tree (Yucca brevifolia) and eastern Joshua tree (Yucca jaegeriana). Eastern Joshua tree (Yucca brevifolia ssp. jaegeriana) distribution is represented in the data incidentally, but the primary purpose of this dataset is to illustrate the distribution of western Joshua tree. Western Joshua tree is distributed in discontinuous populations in the Mojave Desert and in a portion of the Great Basin Desert. Western Joshua tree is often noted as being abundant near the borders of the Mojave Desert in transition zones. No attempt was made to map Joshua tree distribution outside of California, and therefore the data are limited to geographic areas within California. CDFW possesses vegetation maps that cover a large portion of the California deserts where Joshua tree generally occurs. CDFWs Vegetation Classification and Mapping Program (VegCAMP) uses a combination of aerial imagery and fieldwork to delineate polygons with similar vegetation and to categorize the polygons into vegetation types. In 2013, an effort was made to create a vegetation map that covers a large portion of the California deserts. The vegetation data from this project includes percent absolute cover of Joshua tree and in some instances only Joshua tree presence and absence data. Western Joshua tree and eastern Joshua tree were lumped together as one species in these vegetation maps. A rigorous accuracy assessment of Joshua tree woodland vegetation alliance was performed using field collected data and it was determined to be mapped with approximately 95 percent accuracy. This means that approximately 95 percent of field-verified, polygons mapped as Joshua tree woodland alliance were mapped correctly. While Joshua tree woodland alliance requires even cover of Joshua tree at greater than or equal to 1 percent, the vegetation dataset has polygons recorded with less than 1 percent cover of Joshua tree as well as simple presence and absence data. The CDFW used Joshua tree polygons from vegetation mapping combined with additional point data from other sources including herbarium records, Calflora, and iNaturalist to create the western Joshua tree range boundary used in the March 2022 Status Review of Western Joshua Tree. CDFW reviewed publicly available point observations that appeared to be geographic outliers to ensure that incorrectly mapped and erroneous observations did not substantially expand the presumed range of the species. In a limited region, hand digitized points were used where obvious Joshua tree occurrences that had not been mapped elsewhere were present on aerial photographs. Creating a range map with incomplete presence data can sometimes be misleading because the absence of data does not necessarily mean the absence of the species. Some of the observations used to produce the range map may also be old, particularly if they are based on herbarium records, and trees may no longer be present in some locations. Additionally, different buffer distances around data points can yield wildly different results for occupied areas. To create the the western Joshua tree range boundary used in the March 2022 Status Review of Western Joshua Tree, CDFW buffered presence locations, but did not use a specific buffer value, and instead used the data described above in a geographic information system exercise to extend the range polygons to closely follow known occurrence boundaries while eliminating small gaps between them.

We delineated the existing distribution of western and eastern Joshua trees (Yucca brevifolia and Y. jaegeriana, respectively) with high fidelity across the full range of both species in Arizona, California, Nevada, and Utah, USA. Presences and absences were identified by observers through an intensive visual grid search of online satellite imagery, including a uniform grid of 672,043 cells at a 0.25 square km resolution. Data from the initial satellite surveys was subsequently field validated at 29,050 cells along 15,000 km of driving routes. Where field validation was not possible, experienced observers re-evaluated grid cells using secondary satellite searches in the following three scenarios: 1) cells determined to be without Joshua trees but adjacent to cells having Joshua trees present; 2) cells having Joshua trees present but surrounded by cells without Joshua trees; and 3) cells in areas known to cause confusion because of other issues (e.g., plants, rocky outcrops, fire scars, the urban/wildland interface). The shapefiles provided in this release reproduce the distribution of Joshua trees at high resolution, incorporating all field and satellite validations. By reproducing the current range of the Joshua trees with high fidelity, our dataset can serve as a baseline for future research, monitoring, and management.

Joshua trees (Yucca brevifolia, Y. jaegeriana) are iconic, foundational species of the Mojave and Sonoran Deserts in North America. Due to their ecosystem importance, long generation times, and low resilience to disturbance, these hybridizing sister species are increasingly the focus of conservation efforts. Predicting Joshua tree responses to future climate, along with the extent of suitable future habitat and/or climate change refugia, is critical to ongoing management planning. We used a recent high-resolution, field-validated distributional database of nearly complete presence and absence records (Esque et al. 2023), along with a life-history based model of dispersal capacity (Engler et al. 2012), to project Joshua tree distributions into future time periods and climate scenarios based on species distribution models (SDMs). SDMs predict habitat probabilities (ranging from 0 to 1) for a species of interest by modeling association between known occurrences and environmental covariates and are a primary means of predicting species-level responses to future climate or land management scenarios. In this approach, SDMs are fit to current day or ‘baseline period’ climate and subsequently projected into the same or broader areas using climate variables defined in future time periods and / or emissions scenarios, such as those from the Coupled Model Intercomparison Project phase 6 (CMIP6) representative concentration pathways corresponding to the 6th Intergovernment Panel on Climate Change (IPCC) Assessment Report (IPCC 2021). From the habitat probabilities resulting from future-projected SDMs, reflecting all potential suitable future habitat, climate change refugia can be further defined as areas of predicted future suitable habitat that intersect with currently occupied habitat ('in situ refugia' assuming no dispersal to new habitats; sensu Ashcroft 2010) or areas of suitable future habitat that are likely to be accessible through ordinary means of dispersal (ex situ refugia; sensu Ashcroft 2010). The latter requires pairing SDMs with a model of potential dispersal incorporating aspects of the species biology and life history; for plants, this may include generation times and propagule dispersal mechanism (Engler et al. 2012; Bateman et al. 2013). The combination of in situ and ex situ refugia may be considered the total accessible refugia for a species. This project develops new SDM predictions for Joshua tree’s future habitat suitability and in situ vs. ex situ climate change refugia based on high resolution range mapping, updated future climate assessments, and modeled dispersal capacity. Full citations for references can be found in Analytical Tools or Sources.

Coevolution frequently plays an important role in diversification, but the role of obligate pollination mutualisms in the maintenance of hybrid zones has rarely been investigated. Like most members of the genus Yucca, the two species of Joshua tree (Yucca brevifolia and Yucca jaegeriana) are involved in a tightly coevolved mutualism with yucca moths. There is strong evidence of a history of coevolution between Joshua trees and their moth pollinators. We use a geographic clines approach in the Joshua tree hybrid zone to ask if selection by the moths may currently contribute to maintaining separation between these species. We compare genomic, phenotypic, and pollinator frequency clines to test whether pollinators maintain the hybrid zone or follow it as passive participants. The results reveal dramatic overlapping genomic and pollinator clines, consistent with a narrow hybrid zone maintained by strong selection. Wider phenotypic clines and a chloroplast genomic cline displaced opposite the expected direction suggest that pollinators are not the main source of selection maintaining the hybrid zone. Rather, it seems that high levels of reproductive isolation, likely acting through multiple barriers and involving many parts of the genome, keep the hybrid zone narrow.

This dataset was collected as an NCALM Seed grant for PI Ann Hislop, University of Kentucky, for the purpose of studying the tectonic linkage between the San Andreas Fault and the Eastern California Shear Zone, Little San Bernardino Mountains, Joshua Tree National Park, California.

Publications associated with this dataset can be found at NCALM's Data Tracking Center

This dataset tracks annual distribution of students across grade levels in Joshua Tree Elementary School

Fossil records documenting late Pleistocene Joshua tree distribution and Holocene migration rates.

These data were compiled to measure the stand structure, including age class distribution, of Joshua tree (Yucca brevifolia and Y. jaegeriana) as measured on 61 1000 m2 plots.The objective of our study was to provide the U.S. Fish and Wildlife Service with demographic data, particularly on recruitment, of the Joshua trees for their use in decisions that the Service makes for the management of Joshua trees. These data represent tree height, number of trees by age class as represented by height, and some environmental characteristics of each plot. These data were collected in the spring and early fall 2022 in the eastern Mojave of California with plot locations adjacent to plots that had been allocated in 1997 using a stratified random sampling design. The plots naturally had a more northern group and a more southern group on Bureau of Land Management, the Mojave National Preserve, and Death Valley National Park lands. These data were collected with field observations by technicians of the U.S. Geological Survey. The data provide a summary of Joshua tree stand structure including recruitment of trees. Recruitment data for the Joshua tree in the easter Mojave will benefit the decisions that the public land managers make for the long-term viability of the Joshua tree.

This dataset, located within Joshua Tree National Park, CA, was collected as an NCALM Seed grant for Katherine Anna Guns, University of Arizona, Geosciences Department to support an investigation of possible slip rates on the Southern San Andreas Fault through the Eastern Transverse Ranges. The requested survey area is located approximately 31 km east of Palm Springs, CA. The polygon encloses approximately 64 km2.Publications associated with this dataset can be found at NCALM's Data Tracking Center

This data set maps and describes the geology of the San Bernardino Wash 7.5 minute quadrangle, Riverside County, southern California. The quadrangle, situated in Joshua Tree National Park in the eastern Transverse Ranges physiographic and structural province, encompasses parts of the northwestern Eagle Mountains, east-central Pinto Basin, and eastern Pinto Mountains. The quadrangle is underlain by a basement terrane comprising metamorphosed Proterozoic strata, Mesozoic plutonic rocks, and Jurassic and Mesozoic and (or) Cenozoic hypabyssal dikes. The basement terrane is capped by a widespread Tertiary erosion surface preserved in remnants in the Pinto and Eagle Mountains and buried beneath Cenozoic deposits in Pinto Basin. Locally, a cover of Miocene sedimentary deposits and basalt overlie the erosion surface. A sequence of at least three Quaternary pediments is planed into the north piedmont of the Eagle Mountains, each in turn overlain by successively younger residual and alluvial, surficial deposits. The Tertiary erosion surface is deformed and broken by north-northwest-trending, high-angle, dip-slip faults in the Pinto and Eagle Mountains and an east-west trending system of high-angle dip- and left-slip faults along the range fronts facing Pinto Basin. In and around the San Bernardino Wash quadrangle, faults of the north-northwest-trending set displace Miocene sedimentary rocks and basalt deposited on the Tertiary erosion surface and some of the faults may offset Pliocene and (or) Pleistocene deposits that accumulated on the oldest pediment. Faults of this system appear to be overlain by Pleistocene deposits that accumulated on younger pediments. East-west trending faults are younger than and perhaps in part coeval with faults of the northwest-trending set. The San Bernardino Wash database was created using ARCVIEW and ARC/INFO, which are geographical information system (GIS) software products of Envronmental Systems Research Institute (ESRI). The database comprises five coverages: (1) a geologic layer showing the distribution of geologic contacts and units; (2) a structural layer showing the distribution of faults (arcs) and fault ornamentation data (points); (3) a layer showing the distribution of dikes (arcs); a structural point data layer showing (4) bedding and metamorphic foliation attitudes, and (5) cartographic map elements, including unit label leaders and geologic unit annotation. The dataset also includes a scanned topographic base at a scale of 1:24,000. Within the database coverages, geologic contacts , faults, and dikes are represented as lines (arcs and routes), geologic units as areas (polygons and regions), and site-specific data as points. Polygon, region, arc, route, and point attribute tables uniquely identify each geologic datum and link it to descriptive tables that provide more detailed geologic information. The digital database is accompanied by two derivative maps: (1) A portable document file (.pdf) containing a navigable graphic of the geologic map on a 1:24,000 topographic base and (2) a PostScript graphic-file containing the geologic map on a 1:24,000 topographic base. Each of these map products is accompanied by a marginal explanation consisting of a Description of Map Units (DMU), a Correlation of Map Units (CMU), and a key to point and line symbols. The database is further accompanied by three document files: (1) a readme that lists the contents of the database and describes how to access it, (2) a pamphlet file that describes the geology of the quadrangle and (3) this metadata file.

The Spring Mountains are critical habitat for the Spring Mountains mule deer herd in southern Nevada. The Spring Mountains west of Las Vegas, Nevada range in elevation from low meadows at 3,000 ft (910 m) to Charleston Peak at nearly 12,000 ft (3,632 m). Lower elevations are dominated by desert scrub and shrubland transitioning to Yucca brevifolia (Joshua tree) and pinyon-juniper forest at midelevations, with mixed montane conifer including ponderosa pine and Pinus longaeva (bristlecone pine) pine at higher elevations, and sparse alpine grasses and forbs above the tree line. The migratory behavior of the Spring Mountains mule deer herd is variable, with a mix of year-round residents and short-distance elevational migrants. Lovell Canyon serves as a well-used corridor between high-elevation summer range near Mount Charleston and low-elevation winter range near Mountain Springs (fig. 12). In 2020, a wildlife underpass was completed to facilitate movement across State Route 160 and reduce wildlife-vehicle collisions. Most of the land in the Spring Mountains is managed by the FS and the BLM and serves as a popular, year-round recreational destination. Encroaching development, prolonged drought conditions, wildfires, feral equids, and human recreation affect the persistence of the mule deer herd in the Spring Mountains. These mapping layers show the _location of the Migration routes for mule deer (Odocoileus hemionus) in the Spring Mountains population in Nevada. They were developed from 61 winter sequences collected from a sample size of 31 animals comprising GPS locations collected every 1−13 hours.

This data set maps and describes the geology of the Pinto Mountain 7.5 minute quadrangle, Riverside County, southern California. The quadrangle, situated in Joshua Tree National Park in the eastern Transverse Ranges physiographic and structural province, encompasses parts of the northeastern Hexie Mountains, central Pinto Mountains, and central Pinto Basin. The quadrangle is underlain by a basement terrane comprising Proterozoic metamorphic rocks, Mesozoic plutonic rocks, and Mesozoic and Mesozoic and (or) Cenozoic hypabyssal dikes. The basement terrane is capped by a widespread Tertiary erosion surface preserved in remnants in the Hexie and Pinto Mountains and buried beneath Cenozoic deposits in Pinto Basin. Locally, a cover of Miocene sedimentary deposits and basalt overlie the erosion surface. Quaternary and (or) Tertiary lacustrine deposits crop out in the center of Pinto Basin and interfinger laterally with sandstone, conglomerate, and debris flows originating in the Pinto and Hexie Mountains. A sequence of at least three Quaternary pediments is planed into the north piedmonts of the Hexie and Eagle Mountains, each in turn overlain by successively younger residual and alluvial, surficial deposits. The Tertiary erosion surface is deformed and broken by north-northwest-trending, high-angle, dip-slip faults in the Pinto and Eagle Mountains and an east-west trending system of high-angle dip- and left-slip faults along the range fronts facing Pinto Basin. In and around the Pinto Mountain quadrangle, faults of the north-northwest-trending set displace Miocene sedimentary rocks and basalt deposited on the Tertiary erosion surface and some of the faults may offset Pliocene and (or) Pleistocene deposits that accumulated on the oldest pediment. Faults of this system appear to be overlain by Pleistocene deposits that accumulated on younger pediments. East-west trending faults are younger than and perhaps in part coeval with faults of the northwest-trending set. The Pinto Mountain database was created using ARCVIEW and ARC/INFO, which are geographical information system (GIS) software products of Envronmental Systems Research Institute (ESRI). The database comprises eight coverages: (1) a geologic layer showing the distribution of geologic contacts and units; (2) a structural layer showing the distribution of faults (arcs) and fault ornamentation data (points); (3) a layer showing the distribution of dikes (arcs); structural point data layers showing (4) bedding attitudes, (5) foliation attitudes, (6) lineations, (7) minor fold axes; and (8) cartographic map elements, including unit label leaders and geologic unit annotation. The dataset also includes a scanned topographic base at a scale of 1:24,000. Within the database coverages, geologic contacts , faults, and dikes are represented as lines (arcs and routes), geologic units as areas (polygons and regions), and site-specific data as points. Polygon, region, arc, route, and point attribute tables uniquely identify each geologic datum and link it to descriptive tables that provide more detailed geologic information. The digital database is accompanied by two derivative maps: (1) A portable document file (.pdf) containing a navigable graphic of the geologic map on a 1:24,000 topographic base and (2) a PostScript graphic-file containing the geologic map on a 1:24,000 topographic base. Each of these map products is accompanied by a marginal explanation consisting of a Description of Map Units (DMU), a Correlation of Map Units (CMU), and a key to point and line symbols. The database is further accompanied by three document files: (1) a readme that lists the contents of the database and describes how to access it, (2) a pamphlet file that describes the geology of the quadrangle, and (3) this metadata file.

The data set for the Porcupine Wash quadrangle has been prepared by the Southern California Areal Mapping Project (SCAMP), a cooperative project sponsored jointly by the U.S. Geological Survey and the California Division of Mines and Geology. The Porcupine Wash data set represents part of an ongoing effort to create a regional GIS geologic database for southern California. This regional digital database, in turn, is being developed as a contribution to the National Geologic Map Database of the National Cooperative Geologic Mapping Program of the USGS. The Porcupine Wash database has been prepared in cooperation with the National Park Service as part of an ongoing project to provide Joshua Tree National Park with a geologic map base for use in managing Park resources and developing interpretive materials.

The digital geologic map database for the Porcupine Wash quadrangle has been created as a general-purpose data set that is applicable to land-related investigations in the earth and biological sciences. Along with geologic map databases in preparation for adjoining quadrangles, the Porcupine Wash database has been generated to further our understanding of bedrock and surficial processes at work in the region and to document evidence for seismotectonic activity in the eastern Transverse Ranges. The database is designed to serve as a base layer suitable for ecosystem and mineral resource assessment and for building a hydrogeologic framework for Pinto Basin.

This data set maps and describes the geology of the Porcupine Wash 7.5 minute quadrangle, Riverside County, southern California. The quadrangle, situated in Joshua Tree National Park in the eastern Transverse Ranges physiographic and structural province, encompasses parts of the Hexie Mountains, Cottonwood Mountains, northern Eagle Mountains, and south flank of Pinto Basin. It is underlain by a basement terrane comprising Proterozoic metamorphic rocks, Mesozoic plutonic rocks, and Mesozoic and Mesozoic or Cenozoic hypabyssal dikes. The basement terrane is capped by a widespread Tertiary erosion surface preserved in remnants in the Eagle and Cottonwood Mountains and buried beneath Cenozoic deposits in Pinto Basin. Locally, Miocene basalt overlies the erosion surface. A sequence of at least three Quaternary pediments is planed into the north piedmont of the Eagle and Hexie Mountains, each in turn overlain by successively younger residual and alluvial deposits.

The Tertiary erosion surface is deformed and broken by north-northwest-trending, high-angle, dip-slip faults and an east-west trending system of high-angle dip- and left-slip faults. East-west trending faults are younger than and perhaps in part coeval with faults of the northwest-trending set.

The Porcupine Wash database was created using ARCVIEW and ARC/INFO, which are geographical information system (GIS) software products of Environmental Systems Research Institute (ESRI). The database consists of the following items: (1) a map coverage showing faults and geologic contacts and units, (2) a separate coverage showing dikes, (3) a coverage showing structural data, (4) a scanned topographic base at a scale of 1:24,000, and (5) attribute tables for geologic units (polygons and regions), contacts (arcs), and site-specific data (points). The database, accompanied by a pamphlet file and this metadata file, also includes the following graphic and text products: (1) A portable document file (.pdf) containing a navigable graphic of the geologic map on a 1:24,000 topographic base. The map is accompanied by a marginal explanation consisting of a Description of Map and Database Units (DMU), a Correlation of Map and Database Units (CMU), and a key to point-and line-symbols. (2) Separate .pdf files of the DMU and CMU, individually. (3) A PostScript graphic-file containing the geologic map on a 1:24,000 topographic base accompanied by the marginal explanation. (4) A pamphlet that describes the database and how to access it. Within the database, geologic contacts , faults, and dikes are represented as lines (arcs), geologic units as polygons and regions, and site-specific data as points. Polygon, arc, and point attribute tables (.pat, .aat, and .pat, respectively) uniquely identify each geologic datum and link it to other tables (.rel) that provide more detailed geologic information.

Map nomenclature and symbols

Within the geologic map database, map units are identified by standard geologic map criteria such as formation-name, age, and lithology. The authors have attempted to adhere to the stratigraphic nomenclature of the U.S. Geological Survey and the North American Stratigraphic Code, but the database has not received a formal editorial review of geologic names.

Special symbols are associated with some map units. Question marks have been added to the unit symbol (e.g., QTs?, Prpgd?) and unit name where unit assignment based on interpretation of aerial photographs is uncertain. Question marks are plotted as part of the map unit symbol for those polygons to which they apply, but they are not shown in the CMU or DMU unless all polygons of a given unit are queried. To locate queried map-unit polygons in a search of database, the question mark must be included as part of the unit symbol.

Geologic map unit labels entered in database items LABL and PLABL contain substitute characters for conventional stratigraphic age symbols: Proterozoic appears as 'Pr' in LABL and as '<' in PLABL, Triassic appears as 'Tr' in LABL and as '^' in PLABL. The substitute characters in PLABL invoke their corresponding symbols from the GeoAge font group to generate map unit labels with conventional stratigraphic symbols.

The Spring Mountains are critical habitat for the Spring Mountains mule deer herd in southern Nevada. The Spring Mountains west of Las Vegas, Nevada range in elevation from low meadows at 3,000 ft (910 m) to Charleston Peak at nearly 12,000 ft (3,632 m). Lower elevations are dominated by desert scrub and shrubland transitioning to Yucca brevifolia (Joshua tree) and pinyon-juniper forest at midelevations, with mixed montane conifer including ponderosa pine and Pinus longaeva (bristlecone pine) pine at higher elevations, and sparse alpine grasses and forbs above the tree line. The migratory behavior of the Spring Mountains mule deer herd is variable, with a mix of year-round residents and short-distance elevational migrants. Lovell Canyon serves as a well-used corridor between high-elevation summer range near Mount Charleston and low-elevation winter range near Mountain Springs (fig. 12). In 2020, a wildlife underpass was completed to facilitate movement across State Route 160 and reduce wildlife-vehicle collisions. Most of the land in the Spring Mountains is managed by the FS and the BLM and serves as a popular, year-round recreational destination. Encroaching development, prolonged drought conditions, wildfires, feral equids, and human recreation affect the persistence of the mule deer herd in the Spring Mountains. These mapping layers show the location of the Migration routes for mule deer (Odocoileus hemionus) in the Spring Mountains population in Nevada. They were developed from 63 migration sequences collected from a sample size of 18 animals comprising GPS locations collected every 1−13 hours.

This data set maps and describes the geology of the Porcupine Wash 7.5 minute quadrangle, Riverside County, southern California. The quadrangle, situated in Joshua Tree National Park in the eastern Transverse Ranges physiographic and structural province, encompasses parts of the Hexie Mountains, Cottonwood Mountains, northern Eagle Mountains, and south flank of Pinto Basin. It is underlain by a basement terrane comprising Proterozoic metamorphic rocks, Mesozoic plutonic rocks, and Mesozoic and Mesozoic or Cenozoic hypabyssal dikes. The basement terrane is capped by a widespread Tertiary erosion surface preserved in remnants in the Eagle and Cottonwood Mountains and buried beneath Cenozoic deposits in Pinto Basin. Locally, Miocene basalt overlies the erosion surface. A sequence of at least three Quaternary pediments is planed into the north piedmont of the Eagle and Hexie Mountains, each in turn overlain by successively younger residual and alluvial deposits. The Tertiary erosion surface is deformed and broken by north-northwest-trending, high-angle, dip-slip faults and an east-west trending system of high-angle dip- and left-slip faults. East-west trending faults are younger than and perhaps in part coeval with faults of the northwest-trending set. The Porcupine Wash database was created using ARCVIEW and ARC/INFO, which are geographical information system (GIS) software products of Envronmental Systems Research Institute (ESRI). The database consists of the following items: (1) a map coverage showing faults and geologic contacts and units, (2) a separate coverage showing dikes, (3) a coverage showing structural data, (4) a scanned topographic base at a scale of 1:24,000, and (5) attribute tables for geologic units (polygons and regions), contacts (arcs), and site-specific data (points). The database, accompanied by a pamphlet file and this metadata file, also includes the following graphic and text products: (1) A portable document file (.pdf) containing a navigable graphic of the geologic map on a 1:24,000 topographic base. The map is accompanied by a marginal explanation consisting of a Description of Map and Database Units (DMU), a Correlation of Map and Database Units (CMU), and a key to point-and line-symbols. (2) Separate .pdf files of the DMU and CMU, individually. (3) A PostScript graphic-file containing the geologic map on a 1:24,000 topographic base accompanied by the marginal explanation. (4) A pamphlet that describes the database and how to access it. Within the database, geologic contacts , faults, and dikes are represented as lines (arcs), geologic units as polygons and regions, and site-specific data as points. Polygon, arc, and point attribute tables (.pat, .aat, and .pat, respectively) uniquely identify each geologic datum and link it to other tables (.rel) that provide more detailed geologic information.

This data set maps and describes the geology of the Conejo Well 7.5 minute quadrangle, Riverside County, southern California. The quadrangle, situated in Joshua Tree National Park in the eastern Transverse Ranges physiographic and structural province, encompasses part of the northern Eagle Mountains and part of the south flank of Pinto Basin. It is underlain by a basement terrane comprising Proterozoic metamorphic rocks, Mesozoic plutonic rocks, and Mesozoic and Mesozoic or Cenozoic hypabyssal dikes. The basement terrane is capped by a widespread Tertiary erosion surface preserved in remnants in the Eagle Mountains and buried beneath Cenozoic deposits in Pinto Basin. Locally, Miocene basalt overlies the erosion surface. A sequence of at least three Quaternary pediments is planed into the north piedmont of the Eagle Mountains, each in turn overlain by successively younger residual and alluvial deposits. The Tertiary erosion surface is deformed and broken by north-northwest-trending, high-angle, dip-slip faults in the Eagle Mountains and an east-west trending system of high-angle dip- and left-slip faults. In and adjacent to the Conejo Well quadrangle, faults of the northwest-trending set displace Miocene sedimentary rocks and basalt deposited on the Tertiary erosion surface and Pliocene and (or) Pleistocene deposits that accumulated on the oldest pediment. Faults of this system appear to be overlain by Pleistocene deposits that accumulated on younger pediments. East-west trending faults are younger than and perhaps in part coeval with faults of the northwest-trending set. The Conejo Well database was created using ARCVIEW and ARC/INFO, which are geographical information system (GIS) software products of Envronmental Systems Research Institute (ESRI). The database consists of the following items: (1) a map coverage showing faults and geologic contacts and units, (2) a separate coverage showing dikes, (3) a coverage showing structural data, (4) a point coverage containing line ornamentation, and (5) a scanned topographic base at a scale of 1:24,000. The coverages include attribute tables for geologic units (polygons and regions), contacts (arcs), and site-specific data (points). The database, accompanied by a pamphlet file and this metadata file, also includes the following graphic and text products: (1) A portable document file (.pdf) containing a navigable graphic of the geologic map on a 1:24,000 topographic base. The map is accompanied by a marginal explanation consisting of a Description of Map and Database Units (DMU), a Correlation of Map and Database Units (CMU), and a key to point-and line-symbols. (2) Separate .pdf files of the DMU and CMU, individually. (3) A PostScript graphic-file containing the geologic map on a 1:24,000 topographic base accompanied by the marginal explanation. (4) A pamphlet that describes the database and how to access it. Within the database, geologic contacts , faults, and dikes are represented as lines (arcs), geologic units as polygons and regions, and site-specific data as points. Polygon, arc, and point attribute tables (.pat, .aat, and .pat, respectively) uniquely identify each geologic datum and link it to other tables (.rel) that provide more detailed geologic information.