Arroyo Burro
Arroyo Burro rises five miles northeast of Ramireño in western Zapata County (at 27°03' N, 99°16' W) and runs southwest for eight miles to its mouth on the Rio Grande, a mile east of Ramireño (at 27°00' N, 99°22' W). It crosses low-rolling to flat terrain with locally active dune blowout areas, surfaced by sand and shallow to deep sandy and clay loams in which grow scrub brush, grasses, scattered oak mottes, mesquite, and chaparral.