Continuing along the High Sierra Trail over the Great Western Divide via Kaweah Gap, one passes from the Kaweah River Drainage, with its characteristic V-shaped river valleys, and into the Kern River drainage, where an ancient fault line has aided glaciers in the last ice age to create a U-shaped canyon that is almost perfectly straight for nearly . On the floor of this canyon, at least two days hike from the nearest road, is the Kern Canyon hot spring, a popular resting point for weary backpackers. From the floor of Kern Canyon, the trail ascends again over to the summit of Mount Whitney. At Mount Whitney, the High Sierra Trail meets with the John Muir Trail and the Pacific Crest Trail, which continue northward along the Sierra crest and into the backcountry of Kings Canyon National Park.