The Hoh Rain Forest is a World Heritage site and it deserves to be one. It is a true temperate rainforest with great old trees, ferns, vines and epiphytes. Disney sent its artists here to study the jungle for the animated movie Tarzan. There are carpets of ferns punctuated by nurse logs, fallen trees that are quickly colonized by ferns, saplings and, it seems, every other green thing in the forest. That line of trees is not an illusion, but an artifact of how new trees establish themselves.
There is a short interpretive trail near the ranger station and a slightly longer loop if you are not energetic, but to get a real sense of the rainforest, take the Hoh RIver Trail. It follows the route of the river and offers some river access, but mainly offers a chance to see the great old trees, most standing, but some fallen by the trail side, some across the trail and sawn through so you can study the tree rings. A good goal is Five Mile Island, about 1:50 from the trailhead. You can wander down to the river, soak your feet in its icy waters and admire the Olympic Mountains upstream. For the less ambitious, head for the waterfall about 1:10 from the trailhead. There is river access near Tom's Creek and a nice view of Mount Tom en route.
Watch for elk. Sometimes they are along the trail, watching you through the bushes. Sometimes they are grazing in the fields of Five Mile Island. Sometimes you don't even have to leave your car, as you'll see them near the ranger station, in the parking lot, or the pond right off the access road.
TIME: Allow at least four hours for a round trip to Five Mile Island, longer if you also want to explore the interpretive trail as well. Allow about two and a half hours for Tom's Creek and the waterfall. You can obviously spend less time here, but why?
NOTES: Relatively easy trail. No dining options at the trailhead. Minimal dining options in Forks. Pack your lunch.
WASP WARNING: During August, there are ground dwelling wasps nesting beside the trail. Most of the nests are marked. Avoid them. If you have a wasp sensitivity, you might want to avoid the trail this time of year.
Time: 4:00, Tom's Creek 2:30, interpretive trail 0:30
Driving time from Port Angeles: 2:00
Admission: ONP admission required
Facilities: Small visitor center with limited hours, water, bathroom, pay phone at trailhead