- The northern boundary of the park is the Winchuck River.
- They run from the Chetco River to their north to the Winchuck River to their South.
- Winchuck River Road runs along or near the north side of the river for much of its course.
- Further downstream, the Winchuck receives Moser Creek and the South Fork Winchuck River, both from the left . The river then leaves Oregon, flowing in Del Norte County, California, for a short distance before re-entering Oregon.
- By comparison, sites on the Winchuck River, the Clackamas, and the North Santiam all scored 95, and a site at a pump station on Klamath Strait Drain between Upper Klamath Lake and Lower Klamath Lake recorded the lowest score in Oregon at 19.