1. Oxalic acid-soluble iron and manganese oxides in the Cambrian Flathead Sandstone, Choteau quadrangle, Montana a sample medium for mineral exploration / [cartographic material] Yale Public content 1981. 2002-06-01T04:00:00Z. 2023-01-31T04:04:30Z. Geological Survey (U.S.). The Survey. English. cartographic image. Public. Montana.