With the washout of the Olympic Hot Springs road, the Elwha valley past the Madison Falls trailhead is now only accessible to hikers (and especially adventurous bicyclists). This road provides access to several hikes.
Griff Creek is a heart-pounding ascent to broad views of the Elwha Valley after a 2-mile road walk from the Madison Falls Trailhead.
Cascade Rock is a shorter but steep hike up out of the valley to a high point. While there's no view, it's a beautiful, quiet walk through the forest.
Glines Canyon Overlook is a former interpretive site where the Elwha Dam used to stand. It provides a great stopping spot for day hikers, including interpretive signage and a stunning view into the canyon that the dam had blocked for years.
Olympic Hot Springs is the ultimate destination on this road for most hikers, but it's also possible to hike all the way through to Appleton Pass and the Seven Lakes Basin (Though you'll need permits to stay there)