Since May 1993, there has been an outbreak of an acute illness with nonspecific symptoms and signs that rapidly progresses to death. The majority of the cases identified have occurred in the rural southwestern United States, predominantly in the four-corners area comprising New Mexico, Arizona, Utah, and Colorado. Findings of preliminary investigation by the Centers for Disease Control and Prevention suggest that the etiologic agent is a previously unidentified strain of Hantavirus. In reported cases, infection with this virus has a very high mortality. The authors describe the primary care of the first Colorado resident of the four Coloradans infected to survive documented Hantavirus-associated disease. There are potential implications for rural healthcare delivery as rapid recognition and early intervention with supportive care could improve survival.