The Bear River is the largest tributary to the Great Salt Lake. Its volume at times reaches 1.4 million acre feet of water. Beginning in Utah's Uinta Mountains, the swift-falling stream first heads north and then changes into a slow meandering stream in Wyoming. It then flows west into Idaho and south into Utah. After flowing nearly 500 miles, it finally empties into Bear River Bay of the Great Salt Lake, ending ninety miles from its place of beginning.

Shoshone Indians lived near the Bear River before Anglo settlement. They were primarily hunter/gatherers who occasionally traded and fought with Cheyenne, Crow, and Blackfoot tribes.

The fur trade brought white trappers to the area. In 1812 Robert Stuart, returning from Astoria, Oregon, heard stories from white men on the Snake River of a river to the south; he was persuaded to take a look at what he later called Miller's River, named after his guide, Joseph Miller. William Sublette led a party in 1824 from the Green River to Soda Springs, the Bear River's northernmost point. So colorful were the stories of the Bear River that the trappers' rendezvous of 1825 and 1827 were held here. Jedediah Smith attended the 1827 rendezvous after his ill-fated California trip. Peter Skene Ogden locally directed the Hudson's Bay Company policy to rid the region of furs in order to discourage American traders and settlers. Other famous trappers who visited the Bear River include B.L.E. Bonneville, Zenos Leonard, Black Harris, and Osborn Russell. Missionaries who visited the river included Jason and Daniel Lee as well as Father Jean Paul De Smet. John Charles Fremont explored the area in 1843 and his report helped prepare the Mormons for their new life in the West.

Some Mormons thought they were coming west to settle the Bear River Valley. They explored the mouth of the Bear in April 1848 in the Mud Hen, a fifteen-foot skiff built from fir planks and launched in the Jordan River at Salt Lake City. The next year, Howard Stansbury and John W. Gunnison, U.S. Topographical Engineers, took Albert Carrington and a crew of men on a circumnavigational expedition of the Great Salt Lake. Their craft was left high on a mud flat in the Bear River Bay when a sudden April snowstorm nearly took their lives. In 1863, during the Civil War, Colonel Patrick Connor took troops north from Salt Lake to Cache Valley in order to chastise some Bannock (Shoshone) Indians who had been raiding emigrant wagon trains. Connor surprised the Indians' winter encampment on the Bear River and killed 250 Indians in what has come to be viewed as a controversial and terrible action.

The James A. Garfield, a paddle-wheeler, carried ore from the south shore of the Great Salt Lake up the Bear River as far as Corinne for transshipment by rail before 1874.

Geologists John W. Powell and G.K. Gilbert reported as early as 1878 that the Bear River waters would generate controversy. The truth of their foresight was proven when one of the first stream-gauging stations in the U.S. was established at Collinston in 1889. Farmers in Wyoming, Idaho, and Utah wanted as much water as they could get and power companies filed for rights. Coming close to Bear Lake but not part of it, the River was joined by an inlet in 1918 in order that river waters could be stored in the lake. Under the 1955 Bear River Compact water rights have been redefined and use is regulated more to the users' satisfaction.