The purpose of this study was to assess the various aspects of public safety related to the thousands of abandoned or inactive underground mines found throughout western Colorado. Review of available published mine inventories yielded data on over 8,000 abandoned underground mines. A random sample of 200 mines was then selected for field visits representative of mining activity in Colorado. Of the 200 mines visited, 20 mine openings representative of varying geologic, environmental, access, and mining conditions were selected for detailed low-cost safeguard application. Volume i comprises descriptions of these safeguards, presented in narrative, itemized labor-materials-equipment tabulations, and illustrations. Research into the regulations of mine closure and safeguards was also undertaken to determine jurisdiction of public lands. Recommendations are suggested to improve the awareness and ability to continue this program into an implementation stage.