OF-01-13 History, Geology, and Environmental Setting of Selected Mines in the Chalk Creek Mining District, Pike/San Isabel National Forest, Chaffee County, Colorado


Describes the history, geology, and environmental setting of selected mines in the Chalk Creek Mining District about 20 miles southwest of Buena Vista in Chaffee County. Includes: introduction, methods of investigation, location and geographic setting, historical overview, geology setting, migration pathways, summary and conclusion, and references. Mining history, geology, site descriptions, and waste and hazard characteristics are given for each individual mine. Digital PDF download. OF-01-13D

From the Author’s Notes:

During the summer of 1995 the Colorado Geological Survey (CGS) inventoried mines in the Chalk Creek area of the Salida Ranger District, Pike/San Isabel National Forest. This project was part of an eight-year, Statewide inventory of abandoned mines on U.S. Forest Service administered lands in Colorado. Not all of the mines were on National Forest System (NFS) lands; in some instances the forest boundary or mine locations were incorrectly located on Primary Base Series (PBS) maps. Some mines close to NFS lands were inventoried, and mines that potentially impacted NFS lands were included. In 1998 and 1999 the U.S. Forest Service requested more detailed studies on selected mines in 13 inventory areas in the Chalk Creek mining district. All of the selected mines had received Environmental Degradation Ratings (EDRs) of 3 (potentially significant) or worse from CGS. This study presents the results of the additional work requested on mines in the Chalk Creek mining district. The following report is organized according to inventory areas.

Many of the smaller mines in the Chalk Creek district were worked in the late 1800s. Very little historical information was available regarding these mines. Without a mine or claim name, historical research is difficult. Locating mining claims from older county records can be difficult or impossible.

Most of the ore in the district occurred in veins, was free smelting, and was composed of galena and other sulfide minerals, with values in silver. In 1998 and 1999 detailed studies were conducted on selected mines in 13 inventory areas in the Chalk Creek mining district identified with potentially significant environmental degradation. Although water samples had been collected at some of the sites in 1995, additional samples and water tests were collected in 1999. In-stream samples were collected from Pomeroy Gulch and Chalk Creek in efforts to “bracket” selected mines or groups of mines and better quantify impacts to the watersheds. In addition, many waste-rock piles were sampled. This publication provides useful data for future water quality investigations or restoration.