1872 On September 26, 1872, an agreement was made with the Shoshone people by which they ceded to the United States that part of their reservation "south of a line beginning at a point on the eastern boundary of the reservation due east of the mouth of the Little Popo-Agie at its junction with the Popo-Agie and running from said point west to the mouth of the Little Popo-Agie; thence up the Popo-Agie to the north fork and up the north fork to the mouth of the canyon; thence west to the western boundary of the reservation."
1876 A treaty with the Sioux people ceded to the United States all that part of Wyoming north of the Platte and Sweetwater Rivers, and extending west to the Rattlesnake Mountains and the Powder River, was ceded to the United States. Congress promptly ratified the agreement and the lands were opened to settlement. Most of the counties of northeastern Wyoming were formed out of the lands obtained by this treaty.
1918 News about the Big Horn Basin appeared in the September 26, 1918 issue of the Douglas Budget.