1. Geology of the northern part of the Boulder bathylith and adjacent area, Montana [cartographic material] Yale Public content 1963. 2012-09-21T15:40:58Z. 2013-03-18T20:28:22Z. Knopf, Adolph, 1882-1966. U.S. Geological Survey. English. Public. Montana, Lewis and Clark County, and Jefferson County.