South Thompson River

South Thompson River
Name origin: The Thompson River was named by Simon Fraser in honour of David Thompson
Country	Canada
Province	British Columbia
Tributaries
- left	Chase Creek, Monte Creek, Campbell Creek
- right	Niskonlith Creek
Source	Little Shuswap Lake
- elevation	347 m (1,138 ft)
- coordinates	50°49′50″N 119°41′29″W / 50.83056°N 119.69139°W / 50.83056; -119.69139
Mouth	Thompson River
- location	Kamloops
- elevation	336 m (1,102 ft)
- coordinates	50°40′50″N 120°20′19″W / 50.68056°N 120.33861°W / 50.68056; -120.33861Coordinates: 50°40′50″N 120°20′19″W / 50.68056°N 120.33861°W / 50.68056; -120.33861
Length	58 km (36 mi)
Basin	18,000 km2 (6,950 sq mi)
Discharge	for Chase
- average	292 m3/s (10,312 cu ft/s)
- max	1,610 m3/s (56,857 cu ft/s)
- min	45.3 m3/s (1,600 cu ft/s)
Thompson River's watershed

The South Thompson River is the southern branch of the Thompson River, the largest tributary of the Fraser River, in the Canadian province of British Columbia. It originates at the outlet of Little Shuswap Lake at the town of Chase and flows approximately 58 kilometres (36 mi) southwest and west through a wide valley to Kamloops where it joins the North Thompson River to form the main stem Thompson River.

Highway 1, the Trans-Canada Highway, and the mainline of the Canadian Pacific Railway parallel the river. Little Shuswap Lake is fed by the Little River, which drains Shuswap Lake, which is fed by several rivers and creeks.

Before 1982 the river was considered to start at the outlet of Shuswap Lake rather than Little Shuswap Lake, but the short river between Shuswap Lake and Little Shuswap Lake was officially renamed Little River in keeping with long-established local usage.

The South Thompson's main tributaries are Chase Creek, which joins from the south at Chase, Niskonlith Creek, which joins from the north near Niskonlith Lake Provincial Park, Monte Creek, which joins from the south at Monte Creek, and Campbell Creek, which joins from the south.