Elwha River Trail is a one trailhead backcountry hiking trail, so in and out is the way to backcountry hike it normally. Elwha River Trail has a total elevation difference of 4,020 feet which is higher than average. This vicinity does get very dry sometimes, so donít forget to check for any current fire restrictions before you go. This walk should take you about 9.5 days, so make sure you've got all your overnight gear packed. This is a long hiking trail, so make sure you bring plenty of supplies. Elwha River Trail goes through some very different elevations which of course means you need to be prepared for different conditions on different parts of the backcountry hiking trail. Elwha River Trail is 64 miles long; it's a long backcountry hiking trail.