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Under contract to the California Department of Fish and Wildlife (CDFW), the North State Planning and Development Collective (NSPDC) created a fine-scale vegetation map of portions of the Sierra Nevada mountains around Lake Tahoe and the adjacent Modoc Plateau. CDFW''s Vegetation Classification and Mapping Program (VegCAMP) provided in-kind service to allocate and score the Accuracy Assessment. The mapping study area consists of approximately 1.6 million acres, covering portions of Sierra, Plumas, Placer, Nevada, Modoc, and Lassen counties. Work was performed on the project between 2019 and 2023. The purposes of the project include assisting land managers in decision-making, fire and fuel management, protecting endangered species and habitats, protecting cultural and natural resources, habitat connectivity, habitat restoration, conservation prioritization, and informed development. NSPDC staff conducted 434 Rapid Assessment and Releve surveys across the mapping area in the summer of 2019 to gather vegetation data to be used in the development of a vegetation classification for the project area.VegCAMP developed the floristic vegetation classification used for the project. The floristic classification follows protocols compliant with the Federal Geographic Data Committee (FGDC) and National Vegetation Classification Standards (NVCS).The vegetation map was produced applying heads-up digitizing techniques using a 2018 base of one-meter National Agricultural Imagery Program (NAIP) imagery (true-color and color infrared), in conjunction with ancillary data and imagery sources. Map polygons are assessed for Vegetation Type, Percent Cover, Exotics, Development Disturbance, and other attributes. The minimum mapping unit (MMU) is 1 acre; exceptions are made for wetlands and riparian types, which were mapped to a 1/4 acre. Breaks on overstory cover were done at 3 acres.Field reconnaissance and the Accuracy Assessment enhanced the overall map quality. There were a total of 107 mapping classes. The overall Fuzzy Accuracy Assessment rating for the final vegetation map,at the Alliance, Group, and Macrogroup levels, is 81.7% percent.

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The California Department of Fish and Game (CDFG) worked collaboratively with the California Native Plant Society (CNPS) and Aerial Information Systems (AIS) to produce a fine-scale vegetation map of the northern Sierra Nevada Foothills region, here defined by the two northern subsections of the USDAs Sierra Nevada Foothills Section (Miles and Goudey 1997). This includes 2.6 million acres of land, with approximately 15 percent under public ownership and 85 percent under private ownership. Vegetation sampling by means of the CNPS Relevé and Rapid Assessment Protocols was used to obtain a total of 710 Relevés and 1691 Rapid Assessments, which were used to develop a quantitative classification based on cluster and indicator species analyses. The resulting classification describes vegetation types according to the National Vegetation Classification System; and was used as a basis for creating a map classification generally at the alliance level, where natural vegetation stands were discernable to that level using 1-meter aerial imagery acquired as part of the National Agricultural Imagery Program (NAIP) in 2005 and 2009. The vegetation map includes 67 map units, of which 54 are natural vegetation map units at the floristic alliance level or higher (group) level and 13 are non-vegetation land use mapping units.

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