The Sangre de Christo Range (sometimes called locally the East Range) is the eastern border of the valley. Mt. Blanca is prominent in the middle of the range. There are several passes at between 9 and 10 thousand feet, La Veta pass being used by US Highway 160 and by the Denver and Rio Grande Railroad (D. & R. G.) tracks. Other passes used historically were Medano, Mosca and Sangre de Christo Passes.
About 50% of the 2 million acres in the San Luis Valley is privately owned.
500,000 acres on the borders of the valley, generally abutting National Forest Lands are managed by the Bureau of Land Management, BLM, a division of the United States Department of the Interior. This land is usually leased to neighboring ranches for grazing for a nominal fee. Part of the value of a ranch is its continuing lease of BLM or National Forest lands.