Questions concerning cultural and biological diversity, cultural homogeneity versus heterogeneity, and biological homogeneity versus heterogeneity are critical to both cultures and biological species. Of the 8 million biological species found on earth, it is hypothesized that 1 million species will become extinct before the year 2000 A.D. Different societies also face a similar threat of cultural extinction. With increasing international, national, regional, and state demands for the preservation of existing habitats in the form of protected reserves, indigenous peoples surrounding or in parks, such as the Navajo at Canyon de Chelly National Monument, are often confronted with rapid change. A conflict exists between the preservation of cultural diversity on the one hand and biological diversity on the other. At Canyon de Chelly National Monument, cultural diversity over time, inclusive of the Anasazi, Navajo, Ute, Spanish, and U.S. cultures, is explored. The management of Canyon de Chelly National Park's cultural diversity and integrity and its biodiversity is also described. Conclusions reached from the study of Canyon de Chelly National Monument are applicable to parks lacking Native American populations. Community inclusion in reserve planning, formation, and management will benefit the crucial long‐term preservation of both cultural and biological diversity.