1. Ferricrete, manganocrete, and bog iron occurrences with selected sedge bogs and active iron bogs and springs in the upper Animas River watershed, San Juan County, Colorado Author/Creator: Yager, Douglas B. Publication/Creation: Denver, Colo. : U.S. Dept. of the Interior, U.S. Geological Survey, 2003 Resource Type: Map Edition: Version 1.1. Access & Availability: Loading