The Mendocino Pygmy Forest is one of the best-known examples of a rare natural community in California. The unique soil and climatic attributes and the resulting vegetation of the Mendocino coastal terraces described by Jenny et al (1969), Westman (1975), Westman and Whittaker (1975), Sholars (1979), Sholars (1982), Sholars (1984) and others are well- known in the scientific and conservation literature.The mapping and classification process assumed that the unique and biologically significant elements of the pygmy forest ecosystem were definable without a complete inventory of the surrounding regional vegetation and land-use patterns. The boundary of the mapped areas was created using existing geographic information on soils, topography, land use, along with fieldwork from previous efforts. Within that area, an array of vegetation samples were collected and classified representing the full array of vegetation patterns within it. The boundary was refined as part of the mapping process. It was later expanded to include property owned by the Mendocino Coast Park and Recreation District after receiving permission to conduct surveys as part of this project. (Polygons that would not have been mapped for the original project but are within the MCPRD property are marked “MCPRD Additional” in the Notes field.)The map was produced using a classification based on an analysis of surveys taken throughout the range of the oligotrophic areas supporting Pygmy Forest vegetation. This classification has been incorporated into the Manual of California Vegetation Online Database. The map classification is mostly at the Association Level of the NVCS hierarchy (12 types), with some at the Alliance Level (5 types) and Group Level (3 types), and 4 land use and water classes. It was hand-digitized using photointerpretation based on the 2014 NAIP Imagery, with other ancillary data used to help with the identification of vegetation types. The minimum mapping unit was 1 acre for vegetation types, and 0.25 acres for water, developed and agricultural type. The total area mapped was 9782 acres.An accuracy assessment performed on the map. The overall accuracy of each of the 5 most reliably sampled types was between 82 and 92 percent accuracy, meeting minimum accuracy standards.For more information, see the supplemental information below and the report for the map cited in the references. https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=161736ReferencesCalifornia Department of Fish and Wildlife, Vegetation Classification and Mapping Program. Classification and Mapping of Pygmy Forest and Related Mendocino Cypress (Hesperocyparis pygmaea) Vegetation, Mendocino and Sonoma Counties, California. CDFW; 11/2018. A Manual of California Vegetation, Online Edition. http://www.cnps.org/cnps/vegetation/. California Native Plant Society, Sacramento, CA.USNVC [United States National Vegetation Classification]. http://usnvc.org/. 2017. United States National Vegetation Classification Database, V2.01. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DCJenny, H. R.J. Arkley, and A.M. Schultz. 1969. The pygmy forest-podsol ecosystem and its dune associates of the Mendocino coast. Madroño20:60-74.Westman, W.E. 1975. Edaphic climax pattern of the pygmy forest region of California. Ecological Monographs30:279-338.Westman, W.E. and R.H. Whittaker. 1975. The pygmy forest region of northern California: studies on biomass and primary productivity. Journal of Ecology63:493-520.Sholars, R.E. 1979. Water relations in the pygmy forest of Mendocino County. Ph.D. diss. University of California, Davis.Sholars, R.E. 1982. The pygmy forest and associated plant communities of coastal Mendocino County, California; genesis, soils, vegetation. Black Bear Press, Mendocino, CA.Sholars, R.E. 1984. The pygmy forest of Mendocino. Fremontia12(3): 3-8.Bowles, C.J. and E. Cowgill. 2012. Discovering marine terraces using airborne LiDAR along the Mendocino-Sonoma coast, northern California. Geosphere8(2):386''402.Soil Survey Staff, Natural Resources Conservation Service (NRCS), United States Department of Agriculture. Web Soil Survey. Available online at https://websoilsurvey.nrcs.usda.gov/. Accessed [October 13, 2014].National Agriculture Imagery Program (NAIP), United States Department of Agriculture. https://www.fsa.usda.gov/programs-and-services/aerial-photography/imagery-programs/naip-imagery/index