The Santiam River (san-tee-AM) is a tributary of the Willamette River, approximately 10 mi (16 km) long, in western Oregon in the United States. Through its two princial 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 mi (13 km) northeast of Albany. It flows generally WNW is slow meandering course to join the Willamette from the east approximately 8 mi (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-ft (120 m) deep Detroit Lake in the Cascades. The Santiam is a major source of water supply for Salem, the capital city of Oregon.

See also

• List of Oregon rivers