Sevilleta National Wildlife Refuge in central New Mexico protects a distinctive meeting ground of river corridors, dry uplands, and four major biomes, making it important for both wildlife habitat and scientific research. Established in 1973 with 230,000 acres, it is managed by the U.S. Fish and Wildlife Service with much of the land kept undeveloped for habitat protection and study. The area also has a long human history, from Piro Pueblo occupation before Spanish arrival to its place along El Camino Real, later Spanish and Mexican landholding, U.S. control after the Mexican-American War, ranch ownership, and eventual preservation. It also supports several endangered or threatened species.