The San Juan River is a major tributary of the Colorado River, flowing through the southwestern United States. It originates in the San Juan Mountains of Colorado and travels approximately 383 miles through New Mexico and Utah before joining the Colorado River. The river is known for its scenic canyons and recreational opportunities, including fishing, rafting, and kayaking. The San Juan River also holds cultural significance, as it runs through areas rich in Native American history, particularly the lands of the Navajo Nation. The river's watershed supports diverse ecosystems and is vital for agriculture and water supply in the region.