Natural resource managers have an interest in locating red harvester ant (Pogonomyrex barbatus) mounds because of the negative impact that heavy infestations have on pastures and because of the importance of the ants to the survival of the threatened Texas horned lizard (Phrynosoma cornutum). We evaluated panchromatic QuickBird imagery (450-900 nm; 0.6 m spatial resolution) subjected to computer classification as a tool for detecting red harvester ant mounds. The study focused on two sites located at the Welder Wildlife Refuge (28° 07' 21" N, 97° 21' 51" W). User's accuracy and producer's accuracy of the thematic maps were greater than or equal to 94.0% for the ant mound class, indicating that it is possible to use thematic maps generated from panchromatic QuickBird imagery and computer classification to detect red harvester ant mounds. Natural resource managers can use this imagery to determine the severity of infestations, which should lead to better management decisions.