1. Geologic map and coal sections of the Pearl School quadrangle and the easternmost part of the Bar V Ranch quadrangle, Big Horn County, Montana [cartographic material] Yale Public content 1981. 2002-06-01T04:00:00Z. 2023-02-22T04:01:20Z. Geological Survey (U.S.). The Survey. English. text. Public. Montana, Big Horn County, and Big Horn County (Mont.).