Cow Bayou rises in two forks in southern McLennan County. Cow Bayou traverses flat to rolling prairie with locally steep slopes, surfaced by dark, expansive clays and clay loams.
Local vegetation consists primarily of oak, juniper, mesquite, cacti, and grasses.
The creek was supposedly named for wild cattle that used to graze on its banks. The Handbook of Texas Online. The Texas State Historical Association, 1997,1998,1999.