Teton River (Idaho)

Teton River
Teton River in the canyons northeast of Rexburg
Country	United States
State	Idaho
Source	Confluence of Warm and Drake Creeks
- location	Near Victor, Teton County
- elevation	6,027 ft (1,837 m)
- coordinates	43°36′38″N 111°09′16″W / 43.61056°N 111.15444°W / 43.61056; -111.15444
Mouth	Henrys Fork
- location	Rexburg, Madison County
- elevation	4,829 ft (1,472 m)
- coordinates	43°53′56″N 111°50′21″W / 43.89889°N 111.83917°W / 43.89889; -111.83917Coordinates: 43°53′56″N 111°50′21″W / 43.89889°N 111.83917°W / 43.89889; -111.83917
Length	81.5 mi (131 km)
Basin	1,130 sq mi (2,927 km2)
Discharge	for near St. Anthony, 22 mi (35 km) from the mouth
- average	829 cu ft/s (23 m3/s)
- max	1,700,000 cu ft/s (48,139 m3/s)
- min	103 cu ft/s (3 m3/s)

The Teton River is an 81.5-mile-long (131.2 km)tributary of the Henrys Fork of the Snake River in southeastern Idaho in the United States. It drains through the Teton Valley along the west side of the Teton Range along the Idaho-Wyoming border at the eastern end of the Snake River Plain. Its location along the western flank of the Tetons provides the river with more rainfall than many other rivers of the region.

The Teton River is formed near Victor in Teton County, Idaho, near the Wyoming state line, by the convergence of several small creeks that descend from surrounding mountains. Several of these creeks, including Teton Creek and Darby Creek, descend from the western flank of the Tetons. Trail Creek descends from the Caribou-Targhee National Forest in Idaho, meeting the other creeks from the south. The river flows north in a slow meandering course through a broad flat valley called the Teton Basin (formerly known as "Pierre's Hole"), flanked by the Teton Range to the east and the Big Hole Mountains to the west. Much of the river's upper course in the Teton Basin is surrounded by extensive wetlands.

After emerging from the north end of the Teton Basin, the Teton River enters the nearly inaccessible Teton Canyon, approximately 25 miles (40 km) long, along the Teton-Fremont county line. There it is joined by Badger Creek and Bitch Creek from the east, then turns west, and is joined by Canyon Creek from the south. After passing through the failed Teton Dam site, north and east of Newdale, the Teton River bifurcates into two distributaries some four miles downstream, just north of Teton, one called the South Fork Teton River (also called the South Teton River) and the other called North Fork Teton River (also known as the Teton River). The South Teton River travels generally southwest until it joins Henry's Fork west of Rexburg at the southwest end of a large inland delta region on the Henry's Fork, essentially merging with the delta from the east as one of its channels. The Teton River itself (North Fork Teton) continues to travel west, where it joins the Henry's Fork at Warm Slough.