They are located near where the river empties into Budd Inlet, a southerly arm of Puget Sound in Olympia.

The Deschutes River carved a course through glacial debris left after the Pleistocene ice age until it reached volcanic bedrock, forming the falls as it coursed down to Puget Sound.

[4] Tumwater Falls was the site of New Market, the first European settlement in Western Washington.

[7][8] A dam at 82 feet (25 m) above sea level created a head for the powerhouse and still stands on the Deschutes River.

Prior to the 1952 hatchery operations, the Deschutes river above the Tumwater Falls lacked a natural salmon run.