Sun River

This article is about the river. For the designated place, see Sun River, Montana.

Sun River Medicine River, Pointed Rock River
The headwaters of the Sun River in the Rockies, near Gibson Reservoir
Location of the mouth of the Sun River in Montana
Location
Country	United States
State	Montana
Cities	Fairfield, Sun River, Vaughn, Great Falls
Physical characteristics
Source	North Fork Sun River
• location	Confluence of Open Creek and McDonald Creek, Lewis and Clark County
• coordinates	47°54′43″N 112°58′23″W
• elevation	5,781 ft (1,762 m)
2nd source	South Fork Sun River
• location	Sun Lake, Lewis and Clark County
• coordinates	47°20′07″N 112°53′29″W
• elevation	6,988 ft (2,130 m)
Source confluence
• location	Near Gibson Reservoir, Lewis and Clark County
• coordinates	47°37′47″N 112°51′25″W
• elevation	4,728 ft (1,441 m)
Mouth	Missouri River
• location	Great Falls, Cascade County
• coordinates	47°29′42″N 111°18′43″W
• elevation	3,314 ft (1,010 m)
Length	130 mi (210 km)
Basin size	1,875 sq mi (4,860 km2)
Discharge
• location	Vaughn
• average	669 cu ft/s (18.9 m3/s)
• minimum	20 cu ft/s (0.57 m3/s)
• maximum	53,500 cu ft/s (1,510 m3/s)
Basin features
River system	Missouri River watershed
Tributaries
• left	North Fork Sun River, Muddy Creek
• right	South Fork Sun River, Willow Creek

The Sun River (also called the Medicine River) is a tributary of the Missouri River in the Great Plains, approximately 130 mi (209 km) long, in Montana in the United States. It sits in the Sun River Valley, also commonly referred to as The Valley for short, a river valley in Cascade County. The valley helps support agriculture with access to irrigation.