20 ft contour lines in Placer County, California. The contour data was derived from 1:24000 USGS digital elevation models. This layer is part of a collection of public geospatial datasets produced by the Placer County GIS Division. Placer County Geographic Information Systems. (2020). 20 Foot Contour Lines, Placer County, California, 2020. Placer County Geographic Information Systems. Available at: https://purl.stanford.edu/px234cf7728 This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.