The purpose of this study was to gather a representative sampling of underground mines in various counties in the State of Nevada and to determine which of these mines had openings representing a hazard or threat to the general public. Based on the selection of 157 target mining districts, 200 inactive mines were selected and visited as a representative sample. The sample was categorized and listings were made by county, type of opening, degree of risk associated with the opening, and the closure method recommended. Each mine site was photographed and the name, location, commodity, historical and geologic value, future mining potential, and degree of hazard was recorded. Laws, regulations, and ordinances pertinent to closure of inactive mines were researched and summarized. It was concluded that permanent mine closure is seldom desirable; low cost, easily installed closures of a semipermanent-to-temporary variety are most appropriate; and sufficient legal mechanisms exist to protect the public if and when applied.