The United States Air Force proposes to deploy an advanced, land-based mobile, intercontinental ballistic missile (ICBM) system known as M-X. This system will improve the nation's strategic deterrent force. In this regard, the Air Force is dedicated to meeting national defense goals while conserving natural and human resources. The purpose of this Environmental Impact Statement (EIS) is to document the analyses and studies performed to identify and compare potential impacts of proposed and alternative basing locations and identify the mitigations that are available. This EIS draft will be the basis for further public comment on the proposed project. A final EIS will be prepared in careful consideration of those comments and serve as an input to the decision process on a location for M-X deployment and withdrawal/acquisition of the land to base the system. The Bureau of Land Management, Department of the Interior, is a cooperating agency for this EIS. This EIS is the third in a series of four planned environmental impact statements for M-X. The first was an analysis of the buried trench construction test program (M-X: Buried Trench Construction and Test Program Final EIS). The second addressed full-scale engineering development decisions regarding missile design, basing mode selection, and a flight test program at Vandenberg Air Force Base, California (M-X: Milestone II Final EIS). That EIS was the basis for decisions on the basing mode. It analyzed vertical and horizontal shelters, slope-sided pool, 20-mile trench, and air mobile.