This resource is a member of a series. The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) System (MTS). The MTS represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The All Roads shapefile includes all features within the MTS Super Class "Road/Path Features" distinguished where the MAF/TIGER Feature Classification Code (MTFCC) for the feature in the MTS that begins with "S". This includes all primary, secondary, local neighborhood, and rural roads, city streets, vehicular trails (4wd), ramps, service drives, alleys, parking lot roads, private roads for service vehicles (logging, oil fields, ranches, etc.), bike paths or trails, bridle/horse paths, walkways/pedestrian trails, and stairways.

This shapefile contains tax rate area (TRA) boundaries in Butte County for the specified assessment roll year. Boundary alignment is based on the 2016 county parcel map. A tax rate area (TRA) is a geographic area within the jurisdiction of a unique combination of cities, schools, and revenue districts that utilize the regular city or county assessment roll, per Government Code 54900. Each TRA is assigned a six-digit numeric identifier, referred to as a TRA number. TRA = tax rate area number

Every published digital survey is designated as either ‘Final’, or ‘Provisional’, depending upon its status in a peer review process. Final surveys are peer reviewed with extensive quality control methods to confirm that field attributes reflect the most detailed and specific land-use classification available, following the standard DWR Land Use Legend specific to the survey year. Data sets are considered ‘final’ following the reconciliation of peer review comments and confirmation by the originating Regional Office. During final review, individual polygons are evaluated using a combination of aerial photointerpretation, satellite image multi-spectral data and time series analysis, comparison with other sources of land use data, and general knowledge of land use patterns at the local level.Provisional data sets have been reviewed for conformance with DWR’s published data record format, and for general agreement with other sources of land use trends. Comments based on peer review findings may not be reconciled, and no significant edits or changes are made to the original survey data.The 2004 Butte County land use survey data set was developed by DWR through its Division of Planning and Local Assistance (DPLA). The data was gathered using aerial photography and extensive field visits. The land use boundaries and attributes were digitized and the resultant data went through standard quality control procedures before finalizing. The land uses that were gathered were detailed agricultural land uses, and lesser detailed urban and native vegetation land uses. The data was gathered and digitized by staff of DWR’s Northern District (ND). Quality control procedures were performed jointly by staff at DWR’s DPLA headquarters and ND, under the supervision of Tito Cervantes, Senior Land and Water Use Scientist. This data was developed to aid DWR’s ongoing efforts to monitor land use for the main purpose of determining current and projected water uses. The associated data are considered DWR enterprise GIS data, which meet all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standards version 2.1, dated March 9, 2016. DWR makes no warranties or guarantees - either expressed or implied - as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data. Comments, problems, improvements, updates, or suggestions should be forwarded to gis@water.ca.gov. This data represents a land use survey of Butte County conducted by DWR, Northern District Office staff, under the leadership of Tito Cervantes, Senior Land and Water Use Supervisor. The field work for this survey was conducted during the summer of 2004. ND staff physically visited each delineated field, noting the crops grown at each location. Field survey boundary data was developed using: 1. The aerial photography used for this survey was taken in June of 2004. 9”x9” color photographs were generated from an altitude of about 6,000 feet above ground to produce a 1:24,000 scale photo. 2. The 9”x9” photos were taken to the field and virtually all the areas were visited to positively identify the land use. Site visits occurred July through September 2004. Land use codes were hand written on the photos. 3. Using AUTOCAD, the land use boundaries were digitized from USGS Digital Orthophoto Quarter Quadrangles (DOQQs) and attributes were entered from the field photos (using a standardized digitizing process). 4. After quality control/assurance procedures were completed on each file (DWG), the data was finalized. 5. The linework and attributes from each DWG quad file were brought into ARCINFO and both quad and survey wide coverages were created, and underwent quality checks. The survey wide coverage was then converted to a shapefile using ARCVIEW. The primary focus of this land use survey is mapping agricultural fields. Urban residences and other urban areas were delineated using aerial photo interpretation. Some urban areas may have been missed, especially in forested areas. Before final processing, standard quality control procedures were performed jointly by staff at DWR's Northern District, and at DPLA headquarters under the leadership of Jean Woods, Senior Land and Water Use Supervisor. After quality control procedures were completed, the data was finalized. The positional accuracy of the digital line work, which is based upon the 9' x 9' color photos, is approximately 23 meters. The land use attribute accuracy for agricultural fields is high, because almost every delineated field was visited by a surveyor. The accuracy is 95 percent because some errors may have occurred. Possible sources of attribute errors are: a) Human error in the identification of crop types, b) Data entry errors.

The California Department of Parks and Recreation contracted Geographical Information Center (GIC) to conduct vegetation sampling across multiple California State Vehicle Recreation Areas (SVRA). The purpose of this map is to characterize the vegetation in various SVRAs, which includes Alameda Tesla, Carnegie, Claypit, Heber Dunes, Hollister Hills, Hungry Valley, Oceano Dunes, Ocotillo Wells and Prairie City. The development of this vegetation map was prompted by the passage of Senate Bill 249, in which California Department of Parks and Recreation’s Off-Highway Motor Vehicle Recreation Division (OHMVRD) was charged with meeting new legislative mandates to ensure resources compliance within all SVRAs. These mandates require (among other things) that OHMVRD compile an inventory of native plant communities within each SVRA [PRC 5090.35 (c)(1)]. To meet this requirement, OHMVRD has consulted the California Department of Fish and Wildlife’s Vegetation Classification and Mapping Program (VegCAMP) to source finescale vegetation maps that cover the SVRA footprint, or, if not available, used the VegCAMP methods to develop new finescale vegetation maps. This finescale vegetation map and associated data is intended to provide an inventory of native plant communities, inform the park’s natural resource management planning including the Wildlife Habitat Protection Plan (WHPP), and establish a baseline for measuring future vegetation change. About the individual SVRAs: Alameda Tesla: The finescale vegetation map for the Alameda Tesla area was created in 2021-2022 using CDFW's VegCAMP standard methods. At the time of surveying, this parcel was part of Carnegie SVRA and was sampled and analyzed together with that project, as part of informing the Carnegie SVRA Wildlife Habitat Protection Plan. However, after the legal separation of these two units in 2021, the mapping projects have also been separated. Carnegie: The finescale vegetation map for Carnegie SVRA was created in 2021-2022 for the park's Wildlife Habitat Protection Plan, using CDFW's VegCAMP standard methods. Field surveys were conducted in 2021. This mapping effort was part of a larger project within the Off Highway Motor Vehicle Division of State Parks to create updated vegetation maps and an inventory of native plant communities for each SVRA. When the project began in 2021, Carnegie SVRA and the adjacent Alameda-Tesla area were sampled and analyzed together. However, because of the legal the separation of these two units in 2021, the mapping projects were separated Clay Pit: Clay Pit SVRA is a small, 220-acre park in unincorporated Butte County, three miles southwest of Oroville. It consists of a narrow terrace surrounding a large bowl-shaped depression that was excavated for clay substrate to use in the construction of the Oroville Dam. It was a popular unofficial off-highway vehicle (OHV) riding area, and became an SVRA in 1981. The entire park is designated as open riding, except for an exclusion zone where a drainage canal flows through the park and into the Feather River oxbow. The park frequently floods from rainfall in wet months, and dries out in the summer. Because of the clay substrate, the shallow depressions formed from OHV use create vernal pools in the spring, providing habitat for native vernal pool plant species and branchiopod species. However, due to the history of disturbance and lack of original topography, many species at the park are ruderal non-natives. Heber Dunes: Heber Dunes SVRA is a small, 364-acre park in unincorporated Imperial County, seven miles northeast of Calexico, and is surrounded by agricultural fields, irrigation canals, and an undeveloped parcel owned by California Department of Transportation (CalTrans). It consists of open sand dunes, planted athel tamarisk (Tamarix aphylla) trees, and native and exotic desert scrub vegetation. The entire park is designated as open riding for off-highway vehicles. Hollister Hills: Hollister Hills SVRA is a 6,750 acre park located in northwest San Benito County, eight miles south of the city of Hollister. It is situated within the Gabilan Range of the California Coast ranges, in an area surrounded by primarily by rangelands. Hungry Valley: Hungry Valley SVRA is a 19,800 acre park within the Transverse Mountain Ranges, just south of Tejon Pass and the town of Gorman. The park is surrounded by National Forest land and by Tejon Ranch. Before becoming a SVRA in 1980, the park had a history of homesteading, mining, and unofficial OHV use. Oceano Dunes: This finescale vegetation map for Oceano Dunes SVRA was created to inform the park's Wildlife Habitat Protection Plan, using CDFW's VegCAMP standard methods. Field surveys were conducted in May 2022 by Chico State Geographic Information Center. Linework was conducted by Chico State Geographic Information Center. State Park staff provided edits to the draft map before it was finalized in 2023. An existing finescale map of the park was completed in 2013 (field surveys done in 2012) by MIG, report available here: https://nrm.dfg.ca.gov/documents/ContextDocs.aspx?cat=VegCAMP. Since vegetation in this park shifts frequently, and since large restoration projects have been conducted since the previous mapping effort, it was determined that an update to the map was needed. Chico State's Geographic Information Center (GIC) sampled the park in 2022 and conducted the linework to create this updated finescale vegetation map, with input from State Park staff. Vegetation was classified using a draft classification for the Santa Cruz-Santa Clara counties project, and by consulting with CDFW staff. Since GIC was also sampling and mapping other central coast State Parks in the region at the same time, the data for Pismo Beach is included here. Ocotillo Wells: This vegetation map was created in 2022-2023 to meet the above requirements and inform the Ocotillo Wells Wildlife Habitat Protection Plan. It was created by combining the existing maps from the DRECP mapping project 2016-2017 additions (Reyes et al.2021), and the Anza Borrego (1998) mapping project (See the VegCAMP website). State park staff including Melissa Patten, Leah Gardner, and Casey Paredes, conducted 25 recon surveys and additional map checks in March 2022 to groundtruth some areas, with a focus on the footprint of the older Anza Borrego project. Linework to edit the Anza Borrego project footprint area was done in 2023 using information from field surveys, and heads-up digitizing of NAIP 2020 imagery. Surveys conducted by State Parks staff in March 2022 focused on the Anza Borrego project footprint within the park, and then linework was done to update the vegetation polygons based on field surveys and 2020 NAIP aerial imagery. Prairie City: Prairie City SVRA is a 1,344 acre park located 20 miles east of Sacramento, in an ecological transition zone between the Central Valley and the Sierra foothills. Parts of the park have a history of dredge mining, and mine tailings form mounds and undulating topography in places. Other portions of the current park were formerly owned by Aerojet and used for a rocket engine program, contaminating groundwater and resulting in modern remediation and groundwater treatment efforts in the park, including monitoring and extraction wells. The imagery interpreted was NAIP 2020No accuracy assessment was done because almost all polygons were visited in the field. Minimum Mapping Units: Alameda Tesla, Carnegie, Heber Dunes, Hollister Hills, Hungry Valley, Prairie City.: The minimum mapping unit was 1 acre for upland vegetation types and ¼ acre for wetland vegetation types. Polygons were divided based on a change in cover class according to Braun-Blanquet categories (<1%, 1-5%, >5-15%, >15-25%, >25-50%, >50-75%, >75%). Breaks for the dominant overstory vegetation cover class required a 3-acre minimum mapping unit, and breaks for understory vegetation cover class required a 5-acre minimum mapping unit. Claypit: The minimum mapping unit was 1 acre, and ¼ acre for wetland or special types, which at the park includes only two small riparian stands and one patch of perennial grassland. The herbaceous stands that compose most of the park were split according to cover, but there was no maximum mapping unit size. Ocotillo Wells, Oceano Dunes: No minimum mapping unit was reported. Imagery: NAIP 2020 imagery was used for all SVRAs.

Every published digital survey is designated as either ‘Final’, or ‘Provisional’, depending upon its status in a peer review process. Final surveys are peer reviewed with extensive quality control methods to confirm that field attributes reflect the most detailed and specific land-use classification available, following the standard DWR Land Use Legendspecific to the survey year. Data sets are considered ‘final’ following the reconciliation of peer review comments and confirmation by the originating Regional Office. During final review, individual polygons are evaluated using a combination of aerial photointerpretation, satellite image multi-spectral data and time series analysis, comparison with other sources of land use data, and general knowledge of land use patterns at the local level.Provisional data sets have been reviewed for conformance with DWR’s published data record format, and for general agreement with other sources of land use trends. Comments based on peer review findings may not be reconciled, and no significant edits or changes are made to the original survey data.The 2005 Yuba County land use survey data set was developed by DWR through its Division of Planning and Local Assistance (DPLA). The data was gathered using aerial photography and extensive field visits. The land use boundaries and attributes were digitized and the resultant data went through standard quality control procedures before finalizing. The land uses that were gathered were detailed agricultural land uses, and lesser detailed urban and native vegetation land uses. The data was gathered and digitized by staff of DWR’s Northern District (ND). Quality control procedures were performed jointly by staff at DWR’s DPLA headquarters and ND, under the supervision of Tito Cervantes, Senior Land and Water Use Scientist. This data was developed to aid DWR’s ongoing efforts to monitor land use for the main purpose of determining current and projected water uses. The associated data are considered DWR enterprise GIS data, which meet all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standards version 2.1, dated March 9, 2016. DWR makes no warranties or guarantees - either expressed or implied - as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data. Comments, problems, improvements, updates, or suggestions should be forwarded to gis@water.ca.gov. This data represents a land use survey of Butte County conducted by DWR, Northern District Office staff, under the leadership of Tito Cervantes, Senior Land and Water Use Supervisor. The field work for this survey was conducted during the summer of 2004. ND staff physically visited each delineated field, noting the crops grown at each location. Field survey boundary date was developed using: 1. The aerial photography used for this survey was taken in June of 2005. 9”x9” color photographs were generated from an altitude of about 6,000 feet above ground to produce a 1:24,000 scale photo. 2. The 9”x9” photos were taken to the field and virtually all the areas were visited to positively identify the land use. Site visits occurred July through September 2005. Land use codes were hand written on the photos. 3. Using AUTOCAD, the land use boundaries were digitized from USGS Digital Orthophoto Quarter Quadrangles (DOQQs) and attributes were entered from the field photos (using a standardized digitizing process). 4. After quality control/assurance procedures were completed on each file (DWG), the data was finalized. 5. The linework and attributes from each DWG quad file were brought into ARCINFO and both quad and survey wide coverages were created, and underwent quality checks. The survey wide coverage was then converted to a shapefile using ARCVIEW. The primary focus of this land use survey is mapping agricultural fields. Urban residences and other urban areas were delineated using aerial photo interpretation. Some urban areas may have been missed, especially in forested areas. Before final processing, standard quality control procedures were performed jointly by staff at DWR's Northern District, and at DPLA headquarters under the leadership of Jean Woods, Senior Land and Water Use Supervisor. After quality control procedures were completed, the data was finalized. The positional accuracy of the digital line work, which is based upon the 9' x 9' color photos, is approximately 23 meters. The land use attribute accuracy for agricultural fields is high, because almost every delineated field was visited by a surveyor. The accuracy is 95 percent because some errors may have occurred. Possible sources of attribute errors are: a) Human error in the identification of crop types, b) Data entry errors.

Sierra Nevada Conservancy (SNC) boundary. The boundary was mapped to correspond with statute AB 2600 (2004) and as re-defined in SB 208 (2022). Work on the boundary was completed by CalFire, GreenInfo Network, and the California Department of Fish and Game. Meets and bounds description of the area as defined in statute: PRC Section 33302 (f) defines the Sierra Nevada Region as the area lying within the Counties of Alpine, Amador, Butte, Calaveras, El Dorado, Fresno, Inyo, Kern, Lassen, Madera, Mariposa, Modoc, Mono, Nevada, Placer, Plumas, Shasta, Sierra, Siskiyou, Tehama, Trinity, Tulare, Tuolumne, and Yuba, described as the area bounded as follows: On the east by the eastern boundary of the State of California; the crest of the White/Inyo ranges; and State Routes 395 and 14 south of Olancha; on the south by State Route 58, Tehachapi Creek, and Caliente Creek; on the west by the line of 1,250 feet above sea level from Caliente Creek to the Kern/Tulare County line; the lower level of the western slope’s blue oak woodland, from the Kern/Tulare County line to the Sacramento River near the mouth of Seven-Mile Creek north of Red Bluff; the Sacramento River from Seven-Mile Creek north to Cow Creek below Redding; Cow Creek, Little Cow Creek, Dry Creek, and up to the southern boundary of the Pit River watershed where Bear Creek Mountain Road and Dry Creek Road intersect; the southern boundary of the Pit River watershed; the western boundary of the upper Trinity watershed in the County of Trinity; on the north by the boundary of the upper Trinity watershed in the County of Trinity and the upper Sacramento, McCloud, and Pit River watersheds in the County of Siskiyou; and within the County of Modoc, the easterly boundary of the Klamath River watershed; and on the north in the County of Modoc by the northern boundary of the State of California; excluding both of the following: (1) The Lake Tahoe Region, as described in Section 6605.5 of the Government Code, where it is defined as "region" (2) The San Joaquin River Parkway, as described in Section 32510.

According to GreenInfo Network and the California Department of Fish and Game, the blue oak woodland used to define a portion of the Sierra Nevada Conservancy's western boundary was delineated using referenced vegetation and imagery data.

The 2015 Butte County land use survey data was developed by the State of California, Department of Water Resources (DWR) through its Division of Integrated Regional Water Management (DIRWM) and Division of Statewide Integrated Water Management (DSIWM). Land use boundaries were digitized and land use data were gathered by staff of DWR’s North Central Region using extensive field visits and aerial photography. The land uses that were mapped were detailed agricultural land uses, and lesser detailed urban and native vegetation land uses. The land use data went through standard quality control procedures before final processing. Quality control procedures were performed jointly by staff at DWR’s DSIWM headquarters and North Central Region. This data was developed to monitor land use for the primary purpose of quantifying water use within this study area and determining changes in water use associated with land use changes over time. This data represents a land use survey of Butte County conducted by the California Department of Water Resources, North Central Regional Office staff. Land use field boundaries were digitized with ArcGIS 10.3 using 2014 U.S.D.A National Agriculture Imagery Program (NAIP) one-meter imagery as the base. Agricultural fields were delineated by following actual field boundaries instead of using the centerlines of roads to represent the field borders. Field boundaries were reviewed and updated using 2015 Landsat 8 imagery. Field boundaries were not drawn to represent legal parcel (ownership) boundaries, and are not meant to be used as parcel boundaries. The field work for this survey was conducted during July and August 2015. Images, land use boundaries and ESRI ArcMap software were loaded onto laptop computers that were used as the field data collection tools. Staff took these laptops into the field and virtually all agricultural fields were visited to identify the land use. Global positioning System (GPS) units connected to the laptops were used to confirm the surveyor's location with respect to the fields. Land use codes were digitized in the field using dropdown selections from defined domains. Upon completion of the survey, a Python script was used to convert the data table into the standard land use format. ArcGIS geoprocessing tools and topology rules were used to locate errors for quality control. The primary focus of this land use survey is mapping agricultural fields. Urban residences and other urban areas were delineated using aerial photo interpretation. Some urban areas may have been missed, especially in forested areas. Rural residential land use was delineated by drawing polygons to surround houses and other buildings along with some of the surrounding land. These footprint areas do not represent the entire footprint of urban land. Sources of irrigation water were identified for general areas and occasionally supplemented by information obtained from landowners. Water source information was not collected for each field in the survey, so the water source listed for a specific agricultural field may not be accurate. After quality control procedures were completed, the data was finalized.

The 1999 Butte County land use survey data set was developed by DWR through its Division of Planning and Local Assistance (DPLA). The data was gathered using aerial photography and extensive field visits, the land use boundaries and attributes were digitized, and the resultant data went through standard quality control procedures before finalizing. The land uses that were gathered were detailed agricultural land uses, and lesser detailed urban and native vegetation land uses. The data was gathered and digitized by staff of DWR’s Northern District. Quality control procedures were performed jointly by staff at DWR’s DPLA headquarters and Northern District. Important Points about Using this Data Set: 1. The land use boundaries were drawn on-screen using developed photoquads. They were drawn to depict observable areas of the same land use. They were not drawn to represent legal parcel (ownership) boundaries, or meant to be used as parcel boundaries. 2. This survey was a "snapshot" in time. The indicated land use attributes of each delineated area (polygon) were based upon what the surveyor saw in the field at that time, and, to an extent possible, whatever additional information the aerial photography might provide. For example, the surveyor might have seen a cropped field in the photograph, and the field visit showed a field of corn, so the field was given a corn attribute. In another field, the photograph might have shown a crop that was golden in color (indicating grain prior to harvest), and the field visit showed newly planted corn. This field would be given an attribute showing a double crop, grain followed by corn. The DWR land use attribute structure allows for up to three crops per delineated area (polygon). In the cases where there were crops grown before the survey took place, the surveyor may or may not have been able to detect them from the field or the photographs. For crops planted after the survey date, the surveyor could not account for these crops. Thus, although the data is very accurate for that point in time, it may not be an accurate determination of what was grown in the fields for the whole year. If the area being surveyed does have double or multicropping systems, it is likely that there are more crops grown than could be surveyed with a "snapshot". 3. If the data is to be brought into a GIS for analysis of cropped (or planted) acreage, two things must be understood: a. The acreage of each field delineated is the gross area of the field. The amount of actual planted and irrigated acreage will always be less than the gross acreage, because of ditches, farm roads, other roads, farmsteads, etc. Thus, a delineated corn field may have a GIS calculated acreage of 40 acres but will have a smaller cropped (or net) acreage, maybe 38 acres. b. Double and multicropping must be taken into account. A delineated field of 40 acres might have been cropped first with grain, then with corn, and coded as such. To estimate actual cropped acres, the two crops are added together (38 acres of grain and 38 acres of corn) which results in a total of 76 acres of net crop (or planted) acres. 4. Water source and irrigation method information were collected for this survey, but are not present in this dataset. Contact Tito Cervantes of Northern District for more information about this data. 5. The images (photoquads) are available from Northern District. Contact Tito Cervantes of Northern District for more information about this data. 6. Not all land use codes will be represented in the survey. This dataset has been re-projected into WGS 1984 Web Mercator Auxiliary Sphere from a custom Transverse Mercator projection in NAD 1927.The associated data are considered DWR enterprise GIS data, which meet all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standard version 3.4, dated September 2022. DWR makes no warranties or guarantees - either expressed or implied - as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data. See the CADWR Land User Viewer (gis.water.ca.gov/app/CADWRLandUseViewer) for the most current contact information. Comments, problems, improvements, updates, or suggestions should be forwarded to gis@water.ca.gov.

This data represents a land use survey of Butte County conducted by DWR, Northern District Office staff, under the leadership of Tito Cervantes, Senior Land and Water Use Supervisor. The field work for this survey was conducted during the summer of 2004. ND staff physically visited each delineated field, noting the crops grown at each location. Field survey boundary date was developed using: 1. The aerial photography used for this survey was taken in June of 2005. 9”x9” color photographs were generated from an altitude of about 6,000 feet above ground to produce a 1:24,000 scale photo. 2. The 9”x9” photos were taken to the field and virtually all the areas were visited to positively identify the land use. Site visits occurred July through September 2005. Land use codes were hand written on the photos. 3. Using AUTOCAD, the land use boundaries were digitized from USGS Digital Orthophoto Quarter Quadrangles (DOQQs) and attributes were entered from the field photos (using a standardized digitizing process). 4. After quality control/assurance procedures were completed on each file (DWG), the data was finalized. 5. The linework and attributes from each DWG quad file were brought into ARCINFO and both quad and survey wide coverages were created, and underwent quality checks. The survey wide coverage was then converted to a shapefile using ARCVIEW. The primary focus of this land use survey is mapping agricultural fields. Urban residences and other urban areas were delineated using aerial photo interpretation. Some urban areas may have been missed, especially in forested areas. Before final processing, standard quality control procedures were performed jointly by staff at DWR's Northern District, and at DPLA headquarters under the leadership of Jean Woods, Senior Land and Water Use Supervisor. After quality control procedures were completed, the data was finalized. The positional accuracy of the digital line work, which is based upon the 9' x 9' color photos, is approximately 23 meters. The land use attribute accuracy for agricultural fields is high, because almost every delineated field was visited by a surveyor. The accuracy is 95 percent because some errors may have occurred. Possible sources of attribute errors are: a) Human error in the identification of crop types, b) Data entry errors.