Opal Pool—Willamette National Forest, Oregon: A leap into the refreshingly brisk waters of Opal Pool should come with an automatic membership into the Polar Bear Club -- even during the dog days of summer, the waters hover near a bracing 42 degrees. Luckily, you will have worked up quite a sweat by the time you reach the pool, after a 3.5-mile hike through the old-growth Douglas firs of the Willamette National Forest’s Opal Creek Wilderness Area.
Opal Creek Take Exit 253 Hwy 22 towards Detroit. 22 miles, at flashing yellow light is the Swiss Village Restaurant. Turn left/north onto the North Fork Rd. The Opal Creek trailhead is at the very end of this road, approx 20 miles. 14 miles of pavement then road turns to gravel. After approx 1.5 -2 miles you will see a turn-off on the right towards Three Pools. Stay to the left on Forest Road 2209. Continue another 4 miles to the Opal Creek/Jawbone parking area and trail head.
I've been here, it's lovely - Opal Creek Wilderness in the Willamette National Forest in Oregon -- Opal Creek Valley contains 50 waterfalls, five lakes, and 36 miles of hiking trails with 500-1000 year old trees.