1. Landslide susceptibility map of the Pittsburgh West quadrangle, Allegheny County, Pennsylvania [cartographic material] Yale Public content 1977. 2014-01-17T20:14:11Z. 2014-01-31T23:13:17Z. Pomeroy, John S., 1929-. The Survey. English. Public. Pennsylvania, Allegheny County, and U.S.