There are two theories archeologists believe caused the Fremont to leave the area. The first reason is climatic changes made farming conditions unfavorable, so the Fremont had to return to a more nomadic existence and follow the. animal herds. These people were Numic-speaking Ute, Paiute and Shoshone, whose descendants still live in the Great Basin today. The Fremont may have perished, or they may have integrated into the Numic-speaking groups. The most likely possibility is that the Fremont were forced to move.
Most evidence points toward a northeast migration.
A replacement of Fremont artifacts suggests the Fremont were pushed out and did not join the new groups. The most recent Fremont artifacts, dating from 1500 AD, were, found in the Snake River Plain of Southern Idaho and the Douglas Creek area of Northwest Colorado, the northern and eastern edges of the Fremont's region. The key to understanding the Fremont is variation. The Fremont were settled farmers, growing crops of corn, as well as nomadic desert hunters and gatherers who lived on pine nuts, crickets, and mountain sheep. They were small bands of highly adaptable people living in environments of varied landscapes.