Beginning near Signal Buttes on the western flank of the Cascade Range, the river flows generally west through parts of Mount Hood National Forest to meet the larger river 44 miles (71 km) from its mouth on the Willamette River.

The area is off-limits to commercial logging and mechanized recreation though still open to fishing, camping, hunting, hiking, and many other activities.

[5] The South Fork is also part of the wild and scenic rivers system.

This run is rated Class IV (advanced), on the International Scale of River Difficulty.

Dangers include ledges, boulders, and shifting wood hazards that require scouting and multiple portages.