Subject: Excavation / Access: Public - Yale University Library GeoBlacklight Search Results

1. Map showing relative ease of excavation in the Aspen quadrangle, Pikin County, Colorado [cartographic material]

1972. 2013-04-17T19:32:06Z. 2013-05-02T15:44:45Z. Bryant, Bruce, 1930-. Geological Survey. English. Public. Colorado and Pitkin County.

2. Map showing relative ease of excavation in the Salina quadrangle, Utah

1972. 2012-10-31T13:29:12Z. 2022-12-08T04:41:00Z. Williams, Paul L. (Paul Lincoln), 1932-. U.S. Geological Survey. English. Public. Utah, Sevier County, Piute County, Emery County, Wayne County, and Garfield County.

3. Map showing relative ease of excavation of geologic units in the Henrys Lake quadrangle, Idaho and Montana [cartographic material]

1972. 2013-04-04T19:50:23Z. 2013-04-10T17:34:27Z. Witkind, Irving Jerome, 1917-. U.S. Geological Survey. English. Public. Idaho, Fremont County, Montana, Madison County, Beaverhead County, and Gallatin County.

4. Map showing relative excavatability of geologic materials in the Parker quadrangle, Arapahoe and Douglas Counties, Colorado [cartographic material]

1972. 2013-02-21T19:26:13Z. 2013-03-18T22:37:26Z. Maberry, John O., 1935-. U.S. Geological Survey. English. Public. Colorado, Arapahoe County, and Douglas County.