OBJECTIVES: American Indians who live in rural reservation communities face substantial geographic barriers to care that may limit their use of health services and contribute to their well-documented health disparities. The purpose of this study was to examine the impact of geographical access to care on the use of services for physical and mental health problems and to explore American Indians' use of traditional healing services in relation to use of biomedical services. METHODS: We analyzed survey data collected from 2 tribes (Southwest and Northern Plains). Geographical access to the closest biomedical service was measured using a Geographic Information System, including road travel distance, elevation gain, and reservation boundary crossing. RESULTS: Use of biomedical services was unaffected by geographical access for Northern Plains tribal members with mental health problems and for Southwest tribal members with physical or mental health problems. For members of the Northern Plains tribe with physical health problems, travel distance (P=0.007) and elevation gain (P=0.029) significantly predicted a lower likelihood of service use. The use of traditional healing was unrelated to biomedical service use for members of the Northern Plains tribe with physical or mental health problems and for members of the Southwest tribe with physical health problems. For members of the Southwest tribe with mental health problems, the use of biomedical services increased the likelihood of using traditional healing services. CONCLUSIONS: Findings suggest that biomedical services are geographically accessible to most tribal members and that tribal members are not substituting traditional healing for biomedical treatments because of poor geographical access. Copyright © 2012 by Lippincott Williams & Wilkins.