The San Juan River and its tributaries drain the region known as the Four Corners country—the area surrounding the point where New Mexico, Colorado, Utah, and Arizona meet in a common boundary at right angles. Rising high in the Rocky Mountains of Colorado, the San Juan flows southwestward to dip down into the northwestern corner of New Mexico; then it courses northwestward into Utah almost at the point of juncture of the four states. With many twists and curves, roaring through deep canyons and gulches, it proceeds generally westward to empty into the mighty Colorado River in the southeastern part of Utah.