Near Interstate 5 in Linn County
|Name origin: Kalapuya tribe that lived near the river until removal to the Grande Ronde Reservation|
|County||Linn and Marion|
|Source||confluence of North Santiam and South Santiam rivers|
|- location||Linn and Marion counties, Oregon|
|- elevation||222 ft (68 m) |
|- location||between Albany and Salem, Marion County, Willamette Valley, Oregon|
|- elevation||164 ft (50 m) |
|Length||12 mi (19 km) |
|Basin||1,830 sq mi (4,740 km2)|
|- average||7,714 cu ft/s (218 m3/s)|
|- max||202,000 cu ft/s (5,720 m3/s)|
|- min||260 cu ft/s (7 m3/s)|
The Santiam River (pron.: //) is a tributary of the Willamette River, about 12 miles (19 km) long, in western Oregon in the United States. Through its two principal tributaries, the North Santiam and the South Santiam rivers, it drains a large area of the Cascade Range at the eastern side of the Willamette Valley east of Salem and Corvallis.
The main course of the river is short, formed in the Willamette Valley by the confluence of the North and South Santiam rivers on the border between Linn and Marion counties approximately 8 miles (13 km) northeast of Albany. It flows generally west-northwest in a slow meandering course to join the Willamette from the east approximately 8 miles (13 km) north of Albany.
Both the North and South Santiam rise in high Cascades in eastern Linn County. The Middle Santiam River joins the South Santiam where the South Santiam is impounded to form Foster Lake. The North Santiam is impounded to form the 400-foot (120 m) deep Detroit Lake in the Cascades. The Santiam is a major source of water supply for Salem.
 See also
- McArthur, Lewis A.; McArthur, Lewis L. (2003). Oregon Geographic Names (Seventh ed.). Portland, Oregon: Oregon Historical Society Press. p. 848. ISBN 0-87595-277-1.
- Google Earth elevation for GNIS coordinates
- "Santiam River". Geographic Names Information System (GNIS). United States Geological Survey. November 28, 1980. Retrieved July 24, 2009.
- United States Geological Survey. "United States Geological Survey Topographic Map". TopoQuest. Retrieved July 24, 2009. The maps, which include river mile (RM) markers for the river's entire length, depict the following Oregon quadrants from mouth to source: Monmouth, Sydney, and Albany.
- The Great Willamette Flood of 1861 destroyed numerous towns, most notably Champoeg and Linn City.
- Cain Allen (2004). "The Great Flood of 1861". The Oregon History Project. Oregon Historical Society. Retrieved November 22, 2007.
- Stephenie Flora. "Marion County Flood of 1861". The Oregon Territory and Its Pioneers. Retrieved November 22, 2007.