The authors analyze statistically the first-known example of massive hybridization in darters of the genus Etheostoma. The population was discovered in a disturbed habitat in southern Oklahoma (Blue River: Red River System). Some of the characteristics analyzed were: distance from the union of the gill membranes vs the number of unpored lateral-line scales, number of scale rows below the lateral line vs number of scales above the lateral line, distance from union of gill membranes to pelvic fins vs length of the pelvic fin, and color patterns. The aggregate hybrid index was 42.9, and most of the characteristics tended strongly toward E. spectabile in the hybrids.