Hoh Lake is a quiet spot in the wilderness of Olympic National Park that is accessible via a steep ascent from the Hoh River Trail or a long approach on the High Divide Trail.
To access Hoh Lake from the Hoh River, you'll hike past spectacular old-growth dripping with moss and nurse logs providing nourishment to full-grown trees. The biodiversity on this hike is seldom seen on such an accessible backpacking trip. Just be sure to check in with the ranger station before overnighting — while there are lots of campsites, it's a popular place, and you need to reserve in advance.
From the trailhead, venture down the flat trail through delightful old-growth. Campsites abound here, but be sure to have a reservation or to check in with rangers at the trailhead; in summer especially, most of the sites cannot support drop-ins.
Head into the forest, passing a large sign indicating the mileages to various campsites and landmarks along the way. The first mile of the trail weaves along the banks of the Hoh River, with plenty of lovely views upriver into the forest. This section is also likely to be quite full of other hikers enjoying the area -- the Hoh River Trail to 5-Mile Island is a popular dayhike or a beginner's overnight.
Follow the undulating trail through the forest, past the campsite at 5-Mile Island and on to the next site, Happy 4 (found, oddly, at 5.8 miles in. The shelter is a good place to huddle during a rain, and the campsite makes a nice stopping spot, or lunch spot if you're continuing on.
From here the trail turns away from the river and continues through the forest. The moss on the enormous trees lining the trail dampen noise, and when you're alone the whole area seems muted. In this meditative section, you'll have a log crossing and a short deviation from the riverside, until the next landmark: the Olympus Guard Station, a bit more than 9 miles from the trailhead.
A group camp is here, along with a kiosk with signs showing the relative elevation gain for this trail as well as the trail to Bogachiel Peak and Hoh Lake. The route to the lake and the peak is just 0.6 miles further down the trail from the guard station.
From the junction it's a sweaty 4.7 miles and 3808 feet of elevation to Hoh Lake, as you climb the northern wall of the Hoh River valley. Whew. Luckily the views from the ridge are stunning and only get better as you continue climbing. Once you arrive, kick off your boots and take a load off. You've earned it.
WTA Pro Tip: An alternate way to access Hoh Lake is via the High Divide Trail and Seven Lakes Basin. It's just a 1.8 mile detour with 123 feet of descent accessing it this way, but you still have a multi-mile approach hike and will still need a permit if you hope to camp.