Big Marsh Creek

Big Marsh Creek is a 15 mi tributary of Crescent Creek in Klamath County, in the U.S. state of Oregon. The creek flows generally north from its source upstream of Big Marsh, south of Crescent Lake on the eastern side of the Cascade Range. All of Big Marsh Creek and 10 mi of Crescent Creek are parts of the National Wild and Scenic Rivers System. In turn, Crescent Creek is a tributary of the Little Deschutes River, of which 12 mi in the same general area are also part of the national system.

The upper reaches of Big Marsh Creek flow through the Oregon Cascades National Recreation Area.