Blue Hole is a clear pool on the Ohanapecosh River inside La Wis Wis Campground in the Gifford Pinchot National Forest, a few miles east of Packwood off US Highway 12. It sits in a small canyon only a few hundred yards above the spot where the Ohanapecosh meets the Clear Fork and the two become the Cowlitz River. The Forest Service describes it as a beautiful pool and notes that the Upper Cowlitz people used it as a fishing site.

Getting to the water is about as easy as river swimming gets. Turn into La Wis Wis from US 12, follow the campground road to the Hatchery Loop, and look for the sign for Blue Hole Trail #167. The trail is roughly 100 yards of dirt path through the campground's old-growth Douglas fir, hemlock and cedar, and it ends at an overlook and interpretive site above the pool. It is open to hikers only, with no bikes or horses.

The Ohanapecosh starts at the Ohanapecosh Glacier on the southeast side of Mount Rainier and runs about 16 miles, most of it inside Mount Rainier National Park, before this last stretch through the national forest. It is known for unusually clear water, and the Washington Place Names database says the river's name may mean clear stream or deep blue holes. Expect it to be cold even in August.

The campground is open from mid-May to mid-September and is run by a concessionaire. From mid-September to Memorial Day the entrance is gated at US 12, but the Forest Service says you can still walk down through the campground to reach the trail. Don't block the gate if you park out by the highway. The campground is a fee site, and the Forest Service lists a day-use fee for its picnic area (the amount is not posted online, and holders of Interagency Senior or Access passes get half off). No separate trail permit is required. For the 2026 season there is no drinking water anywhere in the campground because the water system has tested high for benzene, so bring what you need.

La Wis Wis has a long history for a campground. Grant Purcell homesteaded the land in the 1890s and pushed the Forest Service to make it a public park. The Civilian Conservation Corps built the camp in the 1930s, and it was renamed from Clear Fork Campground to La Wis Wis at a large ceremony on July 20, 1935. The Gifford Pinchot National Forest itself was dedicated here in 1949. The 1937 CCC guard station still stands and has been on the National Register of Historic Places since 1986. A bronze plaque in the campground marks the spot where botanists collected Pacific yew bark on August 21, 1962, the sample that led to the cancer drug Taxol.

Grant Purcell Falls Trail #162A also starts from the campground and makes an easy add-on. The Stevens Canyon entrance to Mount Rainier National Park is a short drive up State Route 123, and Paradise is about 28 miles away, which makes Blue Hole a good cool-off after a day in the park.