According to the U. S. Census Bureau, the county has a total area of 3,346 square miles (8,670 km2), of which 3,345 square miles (8,660 km2) is land and 0. 9 square miles (2. 3 km2) (0. 03%) is water. Most of the county is primarily gently-rolling grassland ranging from 6000 to 6200 feet in elevation. The Manzano Mountains rising to 10,098 feet on the western edge of the county provide it with its only significant topographic relief. The Manzano Wilderness area includes the highest part of the mountains. The other notable geographic feature of the county is the series of playas and seasonal lakes centering on Laguna del Perro southeast of Estancia.