"Geology of the Bighorn Mountains", U.S. Geological Survey (USGS)

This report, by Nelson Horatio Darton, focuses on the geology of north-central Wyoming north to Montana and is based upon studies conducted from 1901-1905. Darton, who was hired by G.K. Gilbert in 1886, was one of the earliest geologists to extensively use photography in his field studies, and the visual enhancements brought his research to life. The paper itself features 47 plates including the very colorful Geologic Map of the Bighorn Mountains (19.8 x 37.5") by Darton and the Map Showing Glacial Geology of the Bighorn Mountains (16 x 21") by Salisbury in addition to the numerous attractive photos of the region. 129 pp., disbound.

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Condition: B+

The maps are in good condition with a few short splits at fold intersections. The text and pages are very good with just a hint of toning. Disbound.