Captain William Clark of the Lewis and Clark Expedition named this river for John Shields, a member of the party. Guided by Sacajawea, the Shoshone woman, Clark and his men camped at the mouth of the river on July 15, 1806, while exploring the Yellowstone on their return trip from the coast. In the 1860s, Jim Bridger, a famous trapper, trader, and scout, guided emigrant wagon trains from Fort Laramie, Wyoming, to Virginia City, Montana, across hostile Indian country by way of the Bonanza Trail. His route came up this valley from the Yellowstone, followed Brackett Creek, crossed the divide west of here to reach Bridger Creek, and then went down that stream to the Gallatin Valley.