This is one of the few hikes that I have done multiple times. It's just too nice to pass up. The trailhead is located on the Pacific Crest Trail as it crosses Washington's Hwy 410 at Chinook Pass. Sheep Lake is the quintessential NW subalpine lake nestled in a meadow and surrounded by craggy ridges. It's small, clean, clear and has several pristine camping spots around it. Because we are on the PCT, the elevation gain is minimal so this makes an idea hike for families. Despite being so close to Mt Rainier, there are no views of the mountain from the lake itself, however. For that you'll need to get higher.
Sourdough Gap is a short hike from the lake. At the gap itself you are rewarded with panoramic views to the north and south. On this particular day the weather was warm and pleasant on the south and windy and cold on the north.
Take a side trail towards Crystal Lake once past the Gap and you enter Mt Rainier National Forest (no dogs allowed here) where you can finally see Mt Rainier and head down to Crystal Lake from the top side.
Map & Stats
2.1 mi from trailhead to the lake
400 ft elev gain
3.5 mi from trailhead to Sourdough Gap
1100 ft elev gain
6400 ft highest elev
Northwest Forest Pass required