1. Principal areas of oil, natural gas, and coal production in the northern part of the Front Range, Colorado Yale Public content 2005. 2009-03-31T20:19:46Z. 2018-07-19T15:31:12Z. U.S. Dept. of the Interior, U.S. Geological Survey ; Information Services [distributor]. English. Public. Front Range (Colo. and Wyo.).