1. Map showing flood-prone areas, Boulder-Fort Collins-Greeley area, Front Range Urban Corridor, Colorado [cartographic material] Yale Public content 1975. 2013-05-28T17:19:11Z. 2013-06-14T17:58:04Z. McCain, Jerald F. U.S. Geological Survey. English. Public. Colorado, Boulder County, Larimer County, and Weld County.