The largest Native American reservation in the Southwest United States is Navajo Nation.

Navajo Nation spans approximately 27,000 square miles across northeastern Arizona, northwestern New Mexico, and southeastern Utah, making it the largest Native American reservation in the United States. This vast land area is home to the Navajo people, who have a rich cultural heritage and deep historical ties to the region. The reservation features stunning landscapes, including Monument Valley, Canyon de Chelly, and portions of the Painted Desert. It operates as a sovereign nation with its own government and laws. Navajo Nation is significant not only for its size but also for its cultural and economic contributions to the Southwest.