Samples of Anopheles freeborni s.l. were collected from areas of New Mexico where malaria had once been common and sporozoites had been isolated from this species. Specimens were identified by analysis of polytene chromosome banding patterns and by specific rDNA fragments generated through the polymerase chain reaction. All samples collected in New Mexico were identified as An. hermsi, which was the probable vector of malaria in this region during the early 20th century.