Kit Mountain is a 3,822-foot summit in Brewster County, Texas, in Big Bend National Park’s Chisos Mountains, rising above the Chihuahuan Desert with the Rio Grande about seven miles southwest. Made chiefly of Burro Mesa Formation tuff over the Chisos Formation, it was formed about 29 million years ago during the Oligocene. In a hot, arid setting of hot summers and mild winters, its slopes support desert-adapted plants such as live oak, juniper, piñon pine, and grasses. Although modest in elevation, it rises steeply from nearby ground, gaining about 900 feet in half a mile, and its runoff ultimately drains toward the Rio Grande. Its name has been in use since at least 1912 and may refer to the kit fox.