The five recognized subspecies are American pronghorn (A.a.americana, Ord 1815), Oregon pronghorn (A.a.oregona, Bailey, 1932), Mexican pronghorn (A.a.mexicana, Merriam 1901), Sonoran pronghorn (A.a.sonoriensis, Goldman 1945), and peninsular pronghorn (A.a.peninsularis, Nelson 1912). The relationships and taxonomic validity of these subspecies are poorly known, and many uncertainties exist about their ranges. Populations in which subspecific status was questioned (between American and Mexican pronghorn) include those found in southern New Mexico, southern Arizona, and western Texas *61*(Lee, et al., 1994). The subspecific integrity of pronghorn populations was complicated by restocking that took place after many populations were eliminated in the early twentieth century.