This dataset represents the tiled grid used for processing and organizing the elevation contours covering Napa County at a 2-foot interval. Contour extents were clipped such that they extend 100-ft. beyond the county boundary.

Elevation data was derived from bare-earth surface digital elevation models (DEMs) created from LiDAR data flown in 2018 in response to the widespread 2017 fires in Northern California as part of ongoing nationwide 3DEP (U.S. Geological Survey 3D Elevation Program) efforts.

In limited areas, located along the western edge of the county boundary, supplemental DEMs were acquired from other sources to fill in gaps in the 3DEP data. Use of this supplemental data was negligible, totaling 24 acres out of 507,475 acres countywide (0.005% of total land area).

All DEM tiles (n=41) were merged into a single mosaic. Due to computing limitations, the mosaic was cut into three sections (north, central, and south) of roughly equal size for processing purposes. Two-foot contour lines were generated for each section, then further divided into 1-mile x 1-mile tiles, for a total or 886 tiles.

For metadata or details bout the contours themselves, see the GIS files themselves.