This route begins from the Sol Duc Falls trailhead in the heart of the Olympic National Park, just southwest of Lake Crescent. Beginning in dense, old growth Douglas Fir forest, the route starts with the Sol Duc Nature Trail and follows the Deer Lake Trail to the east. Careening past powerful streams and waterfalls as it climbs into the Deer Lake basin, the route then diverges to the High Divide Trail as it climbs toward Bogachiel Peak.

Here is a nice comprehensive description taken from the Alltrails website:

"A walking trail through the setting of Richard Adams' famous novel, Watership Down. Begin in Newbury, and follow the book through Newtown Common, Ecchinswell, Overton and Whitchurch. You'll see Sandleford Warren, the Enborne River, Nuthanger Farm, Watership Down, Efrafa, the Railway Arch, and the grave of Richard Adams himself."