This is one of the best hikes in Olympic National park. There is a short - Hall of mosses trail which is less than a mile. This one is simply picturesque with epiphytes growing on trees , a tree arch , nursing logs and trees that are 100 yrs old. Then u have the spruce trail and a waterfalls trail. These are slightly longer but worth the effort. There was a Ranger talk at the visitor center, this helped us to learn about the biodiversity and how tree survive in such dense forests. We spent roughly the whole day in Hoh rainforest and I would recommend the same. Watch for elks - if u r lucky , u ll find a herd :)