This part of DS 781 presents data for the depth-to-transition map of the Bolinas to Pescadero, California, region. The raster data file is included in "TransgressiveContours_BolinasToPescadero.zip," which is accessible from https://pubs.usgs.gov/ds/781/BolinasToPescadero/data_catalog_BolinasToPescadero.html. As part of the USGS's California State Waters Mapping Project, a 50-m grid of sediment thickness for the seafloor within the 3-nautical mile limit between Bolinas and Pescadero was generated from seismic-reflection data collected between 2006 and 2010, supplemented with outcrop and geologic structure (fault) information following the methodology of Wong (2012). Water depths determined from bathymetry data were added to the sediment thickness data to provide information on the depth to base of the post-LGM unit. This polyline shapefile provides the depth-to-transition contours to accompany the grid layer. Reference Cited: Wong, F. L., Phillips, E.L., Johnson, S.Y., and Sliter, R.W., 2012, Modeling of depth to base of Last Glacial Maximum and seafloor sediment thickness for the California State Waters Map Series, eastern Santa Barbara Channel, California: U.S. Geological Survey Open-File Report 2012-1161, 16 p. (available at https://pubs.usgs.gov/of/2012/1161/)