AbstractThis article will discuss how Fort Huachuca, in cooperation with The Nature Conservancy and the Bureau of Land Management (BLM), has become the first Army installation to use conservation easements2 to fulfill its responsibility under the Endangered Species Act to conserve endangered and threatened species dependent upon the Upper San Pedro River ecosystem.3 Fort Huachuca sits at the base of the Huachuca Mountains on the western fringe of the San Pedro River Valley in Cochise County, 60 miles southeast of Tucson and 15 miles north of Mexico. The Fort covers 73,142 acres of terrain at elevations ranging from 3,940 feet to 8,625 feet.4 © 2002 Wiley Periodicals, Inc.*