We collected 409 Pimephales vigilax (bullhead minnow) and 32 Percina macrolepida (bigscale logperch) from Elephant Butte Reservoir, Sierra Co., New Mexico, during a small-bodied fish survey in August and December 2005, and January and August 2006. The bullhead minnow is considered nonnative in the Rio Grande in New Mexico, but has been collected downstream of Elephant Butte Reservoir. Collections of this species document its establishment within Elephant Butte Reservoir. The bigscale logperch had not been collected previously from the Rio Grande in New Mexico and these collections represent a range extension for this species. Both species are now established in Elephant Butte Reservoir and these unnatural range extensions are related to human activities, but the exact cause remains unknown.