(Note: this section is a work in progress)
A good summary of VTM and other vegetation mapping efforts in California is Todd Keeler-Wolf's The History Of Vegetation Classification And Mapping In California, a chapter in Terrestrial vegetation of California (3rd ed). Wilmer Colwell's The Status of Vegetation Mapping in California Today from the first edition of Terrestrial vegetation of California (1977) also provides valuable history and descriptions of methodology.
Cooperative Soil-Vegetation Survey
Beginning in 1946 or 1947 as an outgrowth of the VTM survey, federal and state partners collaborated to map soils and vegetation in wildlands of California to assess suitability for livestock and timber harvesting and inform land management activities. Wieslander played a large role in what became know as the State Cooperative Soil-Vegetation Survey. These maps were produced through ~1979. This project is described in this January 1949 publication (also in this article by Wieslander and Storie) The Cooperative Soil-Vegetation Survey resulted in two main map series, plus an additional limited series.
1. Soil-vegetation map (or Vegetation-soil map)
Folders II in Digital Collections (see August 1980 Resource Inventory Maps for quad map and list of quads)
These maps were published on USGS quadrangles at two scales 1:31,680 and 1:24,000 ( 7.5 min USGS scale). Each 1:24,000 sheet represents about 36,000 acres. Polygons of forest and associated species were drawn using a combination of aerial photo interpretation and fieldwork. In addition to mapping vegetation elements, vegetation and soil data was collected at >3000 representative 0.4-ha plots. A document entitled Legends and Supplemental Information to Accompany Soil-Vegetation Maps of California, which allows for the interpretation of symbols in maps published 1963 or earlier, was published in several editions associated with particular quads (e.g., January 1949 / Quad 46 A-3 version; June 1955 / Quad 29 A-3 version; October 1955 / Quad 33 D-1 version). Several versions of a field manual were also published. Maps released following 1963 are usually accompanied by a report including legends and descriptive “tables,” which include lists of observed plant species. The Bioscience Library has a collection of legends and tables, which are organized by quad but not cataloged.
2. Timber stand-vegetation cover
Folders IV in Digital Collections (see August 1980 Resource Inventory Maps for quad map and list of quads)
Timber Stand Vegetation Maps focus on characteristics relevant to timber stand potential and were drawn using aerial photo interpretation. They use blue or black symbols to show broad vegetation types, the density of woody vegetation, age-size, structure, and density of conifer timber stands and other information about the land and vegetation resources is captured. These maps are at a 1:31,680 scale or 7.5 min USGS scale.
3. Upland Soil Maps - These were produced for Mendocino, Glenn, and Lake counties.
Soil Vegetation and Timber Stand Map (national forests). Digital Collections.
Soil Vegetation Map (Mendocino National Forest). Digital Collections.
Soil-vegetation surveys in California national forests that began in 1958; maps published 1962-1973. Similar in scale and methods to the Cooperative Survey's soil vegetation maps. The Bioscience Library has a collection of legends for these maps and related materials, which are not cataloged.
Other California Vegetation Maps
In addition to these multi-year statewide surveys, which were often focused on lands useful for timber or grazing, many one-off vegetation maps of particular locations were produced during the same time period. You can find these (and more recent) vegetation maps at UCB Libraries by searching UC Library Search using keywords like vegetation map, vegetation boundaries, land cover, or phytogeography and limiting your search results to map using the 'resource type' filter. Example: California phytogeography.