They are drained on the west by the Rio Medio, the Rio Quemado, and the Rio de las Trampas; on the northeast by the Rio Santa Barbara; and on the southeast by small creeks that quickly run into the upper reaches of the Pecos River.
These lands are fed by the Rio Medio, Rio Quemado, and Rio de las Trampas flowing from the west; the Rio Santa Barbara flows in from the northeast; and numerous smaller streams feed the upper reaches of the Pecos River to the southeast.