The one successful introduction of a non-native species occurred in 1941 when eighteen buffalo were released north of the mountains. The following year another five bulls were added, and the herd has thrived up to the present. Today they mostly live on the western slopes of the Henrys. During the summer they stay in the higher, cooler elevations, while in the winter they move to Swapp Mesa and Tarantula Mesa west of Mount Pennell. The Utah Department of Wildlife Resources maintains the herd at about 200 individuals. The first buffalo hunt in the Henrys was held in 1950, and a hunt has been held almost every year since 1960.
By the time John Wesley Powell made his pioneering voyage down the Colorado River in 1869, most of the United States was surveyed and mapped. The region around the Henrys, however, remained a blank spot on contemporary maps. Even the peripatetic Spanish explorers failed to leave a lasting name for this range, although it is likely that they were the first whites to notice the mountains from a view point west or south of the Spanish Trail. Neither did the next white men to enter the area, including the French-Canadian trapper Denis Julien; his only known writings are enigmatic inscriptions left in Glen Canyon area of the Colorado River. Jacob Hamblin, the Mormon missionary to the many tribes in the area, surely noticed the Henrys as he traveled back and forth across Glen Canyon in the 1850s, but he too failed to name the mountains. Native American names for the range are not recorded.