G.O. Reid Robert H. Wright 1975 <p>This map shows various types of landslide deposits, scarps, and related topographic features, in addition to other types of surficial deposits, in northernmost Napa County, California.&nbsp; It was prepared by viewing overlapping vertical aerial photographs with a stereoscope.&nbsp; This method allows the geologist to see a three-dimensional model of the terrain to be analyzed and thereby permits him to map the distribution and infer the nature and origin of various landforms.&nbsp; Interpretations were checked by low altitude air reconnaissance in January 1975, but the deposits and features shown on this map have not been checked on the ground.&nbsp; They do, however, represent a consensus of judgment by both authors.</p> application/pdf 10.3133/mf677 en U.S. Geological Survey Photointerpretive map of landslides and surficial deposits of northernmost Napa County, California reports