The Eastern Shoshone migrated to the Rocky Mountain region around the 1600's from the Great Basin Area (Nevada & Utah). By the early 1800's, the Eastern Band of Shoshone ranged along the eastern slope of the Rocky Mountains from Southwestern Wyoming to Southwestern Montana. A nomadic tribe, they moved from place to place in search of food; avoiding harsh winters and hostile tribes. In 1860, a place called Warm Valley, now known as the Wind River Indian Reservation was a place the Eastern Band of Shoshone called home. The area was filled with large amounts of wild game as well as water. The elevation ranged from 5,000 to 14,000 feet in the Rockies, with magnificent views of mountain peaks, valleys, and the rolling plains. During the winter months, the tribe would move camp to the Fort Bridger area, where it was a lot easier to locate food for the people.
In the 1700's, the tribe acquired the horsefrom the Comanche. From collecting roots, seeds, and berries as well as hunting small game to hunting large game such as deer, elk, and buffalo, the horse made everyday life a lot easier for the Eastern Shoshone people. Another change in life included, living in brush shelters to living in tepees, which the horse made moving a lot easier and faster, traveling a greater distance.
The Eastern Shoshone are linguistically and culturally related to other tribes of the Great Basin Area, including the Western Shoshone; Bannock Shoshone; Ute; and Paiute. They are also related to the Comanche Tribe of the southern plains region. Shoshone is a numic language and a part of the larger Uto-Aztecan language family, which once encompassed Native American cultures extending from the Great Basin to Central Mexico.
The Eastern Shoshone were friendly towards American immigrants since their early contact with Lewis & Clark in 1805. Sacajawea, a well known Shoshone woman was enlisted as an interpreter for the Lewis & Clark Expedition. Carrying an infant child, she full-filled her duties, leading the expedition through the Northwest to the Pacific Coast.
In 1840, a young man named Washakie became the principal chief for the Eastern Band of Shoshone Indians, a role he would fulfill until his death. Throughout his reign as chief, he along with his sub-chiefs maintained friendly relations with the U.S. Government and immigrants, who were traveling west in search of a better place to live. Chief Washakie always placed the peace and welfare of his people above all other concerns. In 1900, Chief Washakie passed away, leaving a mark as one of the most respected leaders in American Indian history. Washakie received a full military burial, honoring his leadership in the U.S. Army and for his people.
The Fort Bridger Treaty of 1863 also known as "The Five State Treaty" set the rough boundaries for the Shoshone Reservation. The treaty allowed the Eastern Shoshone a territory of 44,672,000 acres, covering parts of Utah; Idaho; Montana; Colorado; and Wyoming. Several years later, the U.S. Government asked the Eastern Shoshone and Bannock to sign another treaty which was to be held on the same date and place as the 1863 treaty. The Fort Bridger Treaty of 1868 was signed by Chief Washakie and Chief Tyghee, a chief for the Bannock Indians with the help and decision of their sub-chiefs, fixing the exacted boundaries to a much smaller area of 2,774,400 acres in central Wyoming now known as the Wind River Indian Reservation. The Bannocks decided to have their reservation in Eastern Idaho now known as the Fort Hall Indian Reservation since they refused to share a reservation with the Eastern Shoshone. The Eastern Band of Shoshone was also involved with several more treaties following the Fort Bridger Treaty of 1868. These treaties included the Brunot Cession of 1872, McLaughlin Agreement of 1897 & 1904, and Restored Reservation of 1939.