This geologic map database is a reproduction of U.S. Geological Survey Miscellaneous Investigations Map I–2362: “Geologic Map and Structure Sections of the Clear Lake Volcanics, Northern California” (Hearn, Donnelly-Nolan, and Goff, 1995). The database consists of a geologic map, three structural cross sections and a table of petrographic data for each map unit by mineral type, abundance, and size. The Clear Lake Volcanics are in the California Coast Ranges about 150 km north of San Francisco. This Quaternary volcanic field has erupted intermittently since 2.1 million years ago. This volcanic field is considered a high-threat volcanic system (Ewert and others, 2005). The adjacent Geysers geothermal field, the largest power-producing geothermal field in the world, is powered by the magmatic heat source for the volcanic field. The geology of parts of the area underlain by the Cache Formation is based on mapping by Rymer (1981); the geology of parts of the areas underlain by the Sonoma Volcanics, Franciscan assemblage, and Great Valley sequence is based on mapping by McLaughlin (1978). Volcanic compositional map units are basalt, basaltic andesite, andesite, dacite, rhyodacite, and rhyolite, based on SiO2 content. Most ages are potassium-argon (K/Ar) ages determined for whole-rock samples and mineral separates by Donnelly-Nolan and others (1981), unless otherwise noted. A few ages are carbon-14 ages or were estimated from geologic relationships. Magnetic polarities are from Mankinen and others (1978; 1981) or were determined in the field by B.C. Hearn, Jr., using a portable fluxgate magnetometer. Thickness for most units is estimated from topographic relief except where drill-hole data were available. This database does not reproduce all elements of the original publication. Omissions include the chart and figures showing erupted volumes of different lava types through time, and the chart and diagram for the correlation of map units. Users of this database are highly encouraged to cross reference this database with the original publication.

This geologic map database is comprised of new geologic mapping, at a 1:24,000 scale, along the southern Bartlett Springs fault in the northern California Coast Ranges. The map covers an area of 258 square miles in Lake, Napa, Colusa, and Yolo counties, work was undertaken between 2016 and 2021, and supported by the USGS National Cooperative Geologic Map Program. This geodatabase contains the most up-to-date and highest resolution mapping in the region. Results and observations reported here help elucidate the geologic deformational history, as well as relationships between active older and active structures. Please consult the map pamphlet and description of map units for a detailed presentation and interpretation of data and discussion of results. The report and geodatabase contain two plates including the geologic map as well as a correlation of map units, four geologic cross sections, six microseismic cross sections, and a microseismicity fault map.

Abstract not available.

Percent of each freshwater ecoregion’s area covered with lakes and man-made reservoirs.

We calculated the percentage of the ecoregion that is covered by lakes and reservoirs using lake and reservoir polygons from the Global Lakes and Wetlands Database (GLWD) (Lehner and Döll 2004). This database represents the best available source for lakes and wetlands on a global scale (1:1 to 1:3 million resolution). The GLWD contains shoreline polygons of the 3,067 largest lakes (surface area greater than or equal to 50 km2) and 654 largest reservoirs (storage capacity greater than or equal to 0.5 km3) worldwide, as well as shoreline polygons of approximately 250,000 smaller lakes, reservoirs, and rivers (surface area greater than or equal to 0.1 km2). For our calculations, only lake and reservoir polygons were used. It was not possible to separate natural lake polygons from reservoirs.

These data were derived by The Nature Conservancy, and were displayed in a map published in The Atlas of Global Conservation (Hoekstra et al., University of California Press, 2010). More information at http://nature.org/atlas.

Data derived from:

Lehner, B., and P. Döll. 2004. Development and validation of a global database of lakes, reservoirs and wetlands. Journal of Hydrology 296: 1–22.

These data were derived by The Nature Conservancy, and were displayed in a map published in The Atlas of Global Conservation (Hoekstra et al., University of California Press, 2010). More information at http://nature.org/atlas.

For more about The Atlas of Global Conservation check out the web map (which includes links to download spatial data and view metadata) at http://maps.tnc.org/globalmaps.html. You can also read more detail about the Atlas at http://www.nature.org/science-in-action/leading-with-science/conservation-atlas.xml, or buy the book at http://www.ucpress.edu/book.php?isbn=9780520262560

Abstract not available.

The Digital Geologic-GIS Map of the Lake Eleanor Quadrangle, California is composed of GIS data layers and GIS tables, and is available in the following GRI-supported GIS data formats: 1.) a 10.1 file geodatabase (lael_geology.gdb), and a 2.) Open Geospatial Consortium (OGC) geopackage. The file geodatabase format is supported with a 1.) ArcGIS Pro map file (.mapx) file (lael_geology.mapx) and individual Pro layer (.lyrx) files (for each GIS data layer), as well as with a 2.) 10.1 ArcMap (.mxd) map document (lael_geology.mxd) and individual 10.1 layer (.lyr) files (for each GIS data layer). Upon request, the GIS data is also available in ESRI 10.1 shapefile format. Contact Stephanie O'Meara (see contact information below) to acquire the GIS data in these GIS data formats. In addition to the GIS data and supporting GIS files, three additional files comprise a GRI digital geologic-GIS dataset or map: 1.) A GIS readme file (yose_geology_gis_readme.pdf), 2.) the GRI ancillary map information document (.pdf) file (yose_geology.pdf) which contains geologic unit descriptions, as well as other ancillary map information and graphics from the source map(s) used by the GRI in the production of the GRI digital geologic-GIS data for the park, and 3.) a user-friendly FAQ PDF version of the metadata (lael_geology_metadata_faq.pdf). Please read the yose_geology_gis_readme.pdf for information pertaining to the proper extraction of the GIS data and other map files. QGIS software is available for free at: https://www.qgis.org/en/site/. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). For a complete listing of GRI products visit the GRI publications webpage: For a complete listing of GRI products visit the GRI publications webpage: https://www.nps.gov/subjects/geology/geologic-resources-inventory-products.htm. For more information about the Geologic Resources Inventory Program visit the GRI webpage: https://www.nps.gov/subjects/geology/gri,htm. At the bottom of that webpage is a "Contact Us" link if you need additional information. You may also directly contact the program coordinator, Jason Kenworthy (jason_kenworthy@nps.gov). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: U.S. Geological Survey. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (lael_geology_metadata.txt or lael_geology_metadata_faq.pdf). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:62,500 and United States National Map Accuracy Standards features are within (horizontally) 31.8 meters or 104.2 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in ArcGIS, QGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: https://www.nps.gov/articles/gri-geodatabase-model.htm).

This dataset was created using the 123 PISCES extant species range layers listed below in the table. The PISCES datasets were converted to rasters using GIS and then map algebra was used to calculate the total number of species in each huc12 watershed. Using GIS, an extended table was created to provide species lists by watershed using a one to many table relate. Species presence data was provided by PISCES: Moyle, Quinones and Bell (direct addition), Moyle and Randall (gstpoly), . These layers were generated by PISCES on 10/30/2014. The datasets listed in the table below were used in this analysis.Pisces_CodeCommon_NameAAM01Northern Green SturgeonAAT01White sturgeonCCF01Owens SuckerCCO02Goose Lake SuckerCCS01Klamath Largescale SuckerCCA03Clear Lake Prickly SculpinCCG01Riffle SculpinCCK03Upper Klamath Marbled SculpinCCK01Bigeye Marbled SculpinCCK02Lower Klamath Marbled SculpinCCN02Amargosa River PupfishCCN01Saratoga Springs PupfishCCN04Shoshone PupfishCCS03Salt Creek PupfishPEF01Northern California Brook LampreyPES01Klamath River LampreyPET02Goose Lake LampreyPET01Pacific LampreyCGC01Blue ChubCGO01Arroyo ChubEHT03Clear Lake Tule PerchEHT02Russian River Tule PerchEHT01Sacramento Tule PerchPLH01Kern Brook LampreyPLL01Pit-Klamath Brook LampreyPLR01Western Brook LampreyCLE01Sacramento HitchCLE03Monterey HitchCLP01Gualala RoachCLS06Navarro RoachCLS05Monterey RoachCLS04Clear Lake RoachCLS02Red Hills RoachCLS03Russian River RoachCLS07Tomales RoachCLS01Central California RoachCMC01HardHeadSOC01Coastal Cutthroat TroutSOM03Klamath Mountains Province Winter SteelheadSOM04Klamath Mountains Province Summer SteelheadSOM14California Golden TroutSOM12Eagle Lake Rainbow TroutSOM13Kern River Rainbow TroutSOM10McCloud River Redband TroutSOM11Goose Lake Redband TroutSOT08Central Valley Fall Chinook SalmonSOT07Central Valley Late Fall Chinook SalmonSOT03Southern Oregon Northern California Coast Fall Chinook SalmonSOT01Upper Klamath-Trinity Fall Chinook SalmonSOT02Upper Klamath-Trinity Spring Chinook SalmonCCP01Lahontan Mountain SuckerCPM01Sacramento SplittailSPW01Mountain WhitefishCRO06Amargosa Canyon Speckled DaceCRO05Long Valley Speckled DaceCRO04Owens Speckled DaceCRO07Santa Ana Speckled DaceCSB03Lahontan Lake Tui ChubCSB05Eagle Lake Tui ChubCST01Goose Lake Tui ChubCST03Cow Head Tui ChubAAM02Southern Green SturgeonCCL01Lost River SuckerCCM01Modoc SuckerCCO04Humboldt SuckerCCO03Monterey SuckerCCO01Sacramento SuckerCCR01Klamath Smallscale SuckerCCS02Santa Ana SuckerCCT01Tahoe SuckerCCB01Shortnose SuckerCCA04Coastrange SculpinCCA02Prickly SculpinCCA01Rough SculpinCCB02Paiute SculpinCCP03Reticulate SculpinCCP02Pit SculpinCCM02Desert PupfishCCR02Owens PupfishCCS04Cottonball Marsh PupfishGEN01Tidewater GobyCFP01California KillfishGGA01Coastal Threespine SticklebackGGA02Inland Threespine SticklebackGGA04Santa Ana (Shay Creek) SticklebackGGA03Unarmored Threespine SticklebackOHP01Delta SmeltPLA01River LampreyCLE02Clear Lake HitchCLS08Northern (Pit) RoachCLA01Staghorn SculpinMMC02Striped MulletSOC03Lahontan Cutthroat TroutSOC02Paiute Cutthroat TroutSOG01Pink SalmonSOK03Chum SalmonSOK01Central Coast Coho SalmonSOK02Southern Oregon Northern California Coast Coho SalmonSOM05Central California Coast Winter SteelheadSOM06Central Valley SteelheadSOM02Northern California Coast Summer SteelheadSOM01Northern California Coast Winter SteelheadSOM07South Central California Coast SteelheadSOM08Southern California SteelheadSOM09Coastal Rainbow TroutSOM15Little Kern Golden TroutSOT04California Coast Fall Chinook SalmonSOT06Central Valley Spring Chinook SalmonSOT05Central Valley Winter Chinook SalmonCOM01Sacramento BlackfishPPS01Starry FlounderCPG01Sacramento PikeminnowCRO03Klamath Speckled DaceCRO02Lahontan Speckled DaceCRO01Sacramento Speckled DaceCRE01Lahontan RedsideCSB01Klamath Tui ChubCSB04Lahontan Stream Tui ChubCSB06Owens Tui ChubCST02Pit River Tui ChubOST01Longfin SmeltOTP01EulachonCXT01Razorback Sucker

Medicine Lake Well Locations Map

Abstract not available.

The USGS National Hydrography Dataset (NHD) downloadable data collection from The National Map (TNM) is a comprehensive set of digital spatial data that encodes information about naturally occurring and constructed bodies of surface water (lakes, ponds, and reservoirs), paths through which water flows (canals, ditches, streams, and rivers), and related entities such as point features (springs, wells, stream gages, and dams). The information encoded about these features includes classification and other characteristics, delineation, geographic name, position and related measures, a "reach code" through which other information can be related to the NHD, and the direction of water flow. The network of reach codes delineating water and transported material flow allows users to trace movement in upstream and downstream directions. In addition to this geographic information, the dataset contains metadata that supports the exchange of future updates and improvements to the data. The NHD supports many applications, such as making maps, geocoding observations, flow modeling, data maintenance, and stewardship. For additional information on NHD, go to https://www.usgs.gov/core-science-systems/ngp/national-hydrography.

DWR was the steward for NHD and Watershed Boundary Dataset (WBD) in California. We worked with other organizations to edit and improve NHD and WBD, using the business rules for California. California's NHD improvements were sent to USGS for incorporation into the national database. The most up-to-date products are accessible from the USGS website. Please note that the California portion of the National Hydrography Dataset is appropriate for use at the 1:24,000 scale.

For additional derivative products and resources, including the major features in geopackage format, please go to this page: https://data.cnra.ca.gov/dataset/nhd-major-features Archives of previous statewide extracts of the NHD going back to 2018 may be found at https://data.cnra.ca.gov/dataset/nhd-archive.

In September 2022, USGS officially notified DWR that the NHD would become static as USGS resources will be devoted to the transition to the new 3D Hydrography Program (3DHP). 3DHP will consist of LiDAR-derived hydrography at a higher resolution than NHD. Upon completion, 3DHP data will be easier to maintain, based on a modern data model and architecture, and better meet the requirements of users that were documented in the Hydrography Requirements and Benefits Study (2016). The initial releases of 3DHP include NHD data cross-walked into the 3DHP data model. It will take several years for the 3DHP to be built out for California. Please refer to the resources on this page for more information.

The FINAL,STATIC version of the National Hydrography Dataset for California was published for download by USGS on December 27, 2023. This dataset can no longer be edited by the state stewards. The next generation of national hydrography data is the USGS 3D Hydrography Program (3DHP).

Questions about the California stewardship of these datasets may be directed to nhd_stewardship@water.ca.gov.

The Digital Geologic-GIS Map of the Bass Lake Quadrangle, California is composed of GIS data layers and GIS tables, and is available in the following GRI-supported GIS data formats: 1.) a 10.1 file geodatabase (bala_geology.gdb), and a 2.) Open Geospatial Consortium (OGC) geopackage. The file geodatabase format is supported with a 1.) ArcGIS Pro map file (.mapx) file (bala_geology.mapx) and individual Pro layer (.lyrx) files (for each GIS data layer), as well as with a 2.) 10.1 ArcMap (.mxd) map document (bala_geology.mxd) and individual 10.1 layer (.lyr) files (for each GIS data layer). Upon request, the GIS data is also available in ESRI 10.1 shapefile format. Contact Stephanie O'Meara (see contact information below) to acquire the GIS data in these GIS data formats. In addition to the GIS data and supporting GIS files, three additional files comprise a GRI digital geologic-GIS dataset or map: 1.) A GIS readme file (yose_geology_gis_readme.pdf), 2.) the GRI ancillary map information document (.pdf) file (yose_geology.pdf) which contains geologic unit descriptions, as well as other ancillary map information and graphics from the source map(s) used by the GRI in the production of the GRI digital geologic-GIS data for the park, and 3.) a user-friendly FAQ PDF version of the metadata (bala_geology_metadata_faq.pdf). Please read the yose_geology_gis_readme.pdf for information pertaining to the proper extraction of the GIS data and other map files. QGIS software is available for free at: https://www.qgis.org/en/site/. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). For a complete listing of GRI products visit the GRI publications webpage: For a complete listing of GRI products visit the GRI publications webpage: https://www.nps.gov/subjects/geology/geologic-resources-inventory-products.htm. For more information about the Geologic Resources Inventory Program visit the GRI webpage: https://www.nps.gov/subjects/geology/gri,htm. At the bottom of that webpage is a "Contact Us" link if you need additional information. You may also directly contact the program coordinator, Jason Kenworthy (jason_kenworthy@nps.gov). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: U.S. Geological Survey. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (bala_geology_metadata.txt or bala_geology_metadata_faq.pdf). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:62,500 and United States National Map Accuracy Standards features are within (horizontally) 31.8 meters or 104.2 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in ArcGIS, QGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: https://www.nps.gov/articles/gri-geodatabase-model.htm).

During the mid-Pleistocene, eroded sediments from the Colorado Plateau were deposited into the Colorado River Delta to form a natural sediment dam across the Salton Trough. Over time the same actions that formed the dam also altered the course of the Colorado River to flow north, creating periodic stands of water in the Salton Basin. Using LANDSAT-TM images of the Salton Sea Basin, Digital Ortho Quarter Quads and GPS two under-graduate students from the University of Redlands confirmed the elevation of shoreline evidence from Lake Cahuilla at approximately 40 feet above sea level. LANDSAT-TM images of the Salton Sea Basin offered the first preliminary look at possible areas where the shoreline was visible from space. Digital Ortho Quarter Quads were utilized in areas in which the shoreline was not visible from space and for increased accuracy of preliminary shoreline elevations. Global Positioning Units were primarily used to collect control points at areas where shoreline evidence such as tufa deposits, differences in soil composition, or other geomorphic features were present. Using the GPS receiver, clusters of 180 geographic positions were collected for post-processing in the laboratory. Post-processing involved differential correction and determination of a centroid within the point cluster. The control points were then plotted on 7.5-minute digital raster graphics (DRGs). Elevations of the control points were correlated with a digital elevation model (DEM) to produce a shoreline delineation at 11.9m asl. Results Of the fourteen control points taken, three were eliminated due to inconsistencies with GPS satellite telemetry. By differential correction, the remaining 11 control points achieved 95% locational accuracy. This process eliminates 95% of the error introduced by the Department of Defense on the GPS system and distortion from the ionosphere. The 11.9m-contour was plotted on a LANDSAT-TM base image. The shoreline delineation for Mexico was not obtainable due to pending acquisition of digital elevation data for this region. To supplement this, a 10m contour was interpolated with the 11.9m contour used for the California side of Lake Cahuilla. The 11.9m-contour is consistent with the approximated shoreline elevation of Wilke and Waters.

Medicine Lake Map

On October 13, 2020 a survey of Upper Letts Lake was conducted where both bathymetric and terrestrial lidar data were collected. Additionally, six bed material samples and three core samples were collected to understand the characterization of the grain-size of the lake bed. Survey data were merged with an additional lidar dataset from the USGS 3DEP program to create digital elevation model (DEM). The DEM was used to update the stage-storage and stage-surface area tables for the reservoir. This data release provides the following data sets; 1) bathymetric and terrestrial elevation data, 2) Combined bathymetric and 3DEP DEM, 3) stage-storage and stage-surface area tables from DEM, and 4) bed material grain-size and loss of ignition results (percent organics). Results show that the storage for the Upper Letts Lake is 377 acre-feet with a surface area of 34.5 acre at the elevation of the spillway outlet. Bed material samples show that the median diameter of the bed ranges from 0.044 ...

An isostatic residual gravity map of the Big Bear Lake 100,000 scale quadrangle, California was prepared and then this data set used with other information to compute the configuration of several ground water basins. Basin thickness maps were then prepared.

State Water Resources Control Board Division of Water Quality staff have developed this map to graphically display the waterbodies assessed in the 2018 California Integrated Report. This map contains waterbodies assessed for 305(b) categorization, including those placed on the 303(d) list of impaired waters.Map Layers and Table:2018 Integrated Report Streams, Rivers, and Beaches: Spatial representation of the assessed linear waterbodies in California.2018 Integrated Report Lakes, Bays, and Reservoirs: Spatial representation of the non-linear (polygon) waterbodies in California. The layers can also be accessed here: https://gispublic.waterboards.ca.gov/portalserver/rest/services/Hosted/CA_2018_Integrated_Report_Assessed_Lines_and_Polys/FeatureServerHow to Use the Map:Navigate to your point of interest by either using the search bar in the upper left-hand corner of the map or by zooming in on the map. You may enter a waterbody name or address into the search bar. Click on a waterbody of interest, such as a river, lake, or beach, and a pop-up box will appear with a summary of the pollutant assessments conducted for that waterbody. Select the ellipsis ("...") in a pop-up window or the layers to view the attribute table. This table can be further filtered and exported in a tabular format. Click on the layers icon in the upper right hand corner to toggle map layers on and off.Click on the filter button in the upper right corner to filter for a specific Regional Board and to select for 303(d) listed waterbodies only. Note, this should be done for both layers.More details on each waterbody can be found by scrolling to the bottom of a waterbody pop-up and selecting “Waterbody Fact Sheet- More information”.Pop Up Description:WBID: Unique identifier for each waterbody used in the Integrated Report. Waterbody Name: Name of the mapped waterbody assessed for the Integrated Report. Waterbody Type: Type of water (Coastal & Bay Shoreline, Freshwater Wetland, Tidal Wetland, Saline Lake, River & Stream, Ocean, Lake and Reservoir, Estuary, and Bay & Harbor).Regional Board: Which Regional Water Quality Control Board has jurisdiction over the waterbody. Waterbody Condition Category: Integrated Report 305(b) Category for the waterbody.Waterbody Listing Status: If the waterbody has been placed on the 303(d) list as impaired for one or more pollutant, it will be identified as "Listed". If it was assessed for one or more pollutant and not determined to be impaired, it will be identified as "Not Listed". Listed Pollutants: Pollutants identified as impairing the waterbody's support of beneficial uses. The Decision ID is included in parentheses. Listings Addressed by a TMDL: Pollutant impairments in the waterbody being addressed by an adopted Total Maximum Daily Load (TMDL)Listings Addressed by Action other than TMDL: Pollutant impairments in the waterbody being addressed by actions other than a TMDL. These may also be referred to as Category “4b” decisions.Pollutants Assessed, Not Listed: Pollutant assessments that did not result in a 303(d) impairment decision for the waterbody.Waterbody Fact Sheet: Link to the Waterbody Fact Sheet for the waterbody, which includes waterbody/pollutant assessment information. For additional data and information about the 2018 Integrated Report assessments, please visit our Data Download page: (coming soon!)For more information about the Integrated Report (the 305(b) Report and the 303(d) List), how it is created, or how this information is used, please see the program webpage: https://www.waterboards.ca.gov/water_issues/programs/water_quality_assessment/Please contact the SWRCB Water Quality Assessment Program with any questions, at WQAssessment@waterboards.ca.gov. Origin Date: July 2, 2021Last edited: July 28, 2021

Lake dataset created to be used as part of the Water Resources dataset for the Regional Official Plan. ROP Consolidation September 3, 2024.This dataset was created based on the direction provided by the Conservation Authority Working Group, in defining “Lakes and their Littoral Zones”. Data was pulled from MNRF, LSRCA, and TRCA datasets to create this layer.

Geologic map of the Lake Tahoe Basin, California and Nevada, Scale 1:100,000. This map is available as an interactive map, downloadable PDF, and for purchase by contacting the California Geological Survey. For more information see the links provided.

no abstract provided