Sourdough Gap (Mt. Rainier)

Mount Rainier rises above Crystal Lake

6.5 miles round trip, 1100 feet elevation gain
Difficulty: Easy-moderate
Access: Paved road to trailhead, Northwest Forest Pass required

The hike from Chinook Pass to Sourdough Gap in Washington State follows an easy stretch of the Pacific Crest Trail and offers pretty views of lakes, Mount Rainier, and mountain meadows. This pleasant hike starts at a high elevation highway pass, negating the need for a lengthy ascent to reach the Cascades' alpine parklands. The trail passes calm Sheep Lake along the way before climbing gently through meadows to Sourdough Gap; the hike ends not at the gap but just beyond, at a viewpoint over shimmering Crystal Lake. This is a good introduction to hiking from an easily accessed trailhead.

I hiked Sourdough Gap with two friends in August immediately after my thesis defense; having been couped up all month, this was my celebratory hike. We left Seattle on I-5 south, then took Highway 18 east towards Auburn; we exited onto Highway 164, which we followed through the Muckleshoot Reservation to Enumclaw, and then turned left on Highway 410 and followed it into the mountains to Mount Rainier National Park, bearing left at Cayuse Pass to continue along 410 to Chinook Pass. We stopped briefly just short of the pass at a viewpoint over Tipsoo Lake to admire Rainier rising over that small but pretty lake, then continued just over the pass where two parking areas flanked either side of the road. Both parking areas are fine for starting this hike and require a Northwest Forest Pass; those who truly insist on not paying $5 to the US Forest Service can park at Tipsoo Lake in the national park and add a half mile or so each way to this hike.

Mount Rainier rising over Tipsoo Lake

The trail left from the parking area on the left (west/north) side of the road and quickly joined up with the Pacific Crest Trail. The Pacific Crest Trail is the most well known of the West Coast's long distance trails- a 2600-mile jaunt through deserts, the Sierra Nevada, Oregon forests, and the rugged North Cascades from the Mexican border to Canada. While most worthwhile day hike segment along the PCT in Washington State are strenuous to some degree, the hike to Sourdough Gap is an exception, providing a worthwhile and pretty excursion with just a little elevation gain.

We took the right fork upon meeting the PCT to head northbound. The first mile of the hike was more or less flat as it traversed the open slopes above the headwaters of the Rainier Fork American River. There were nice views into the forested U-shaped valley and across to Naches Peak. Looking down the valley, we could see all the way to Goat Peak, one of my favorite hikes for seeing western larch in the autumn. The Highway 410 corridor is one of the easiest and best places to see western larch change color each fall: larches were mixed into the forest of the American River Valley below. Highway 410 was also our constant companion, running just below us on the same slope as it descended towards Yakima. Berry bushes dotted the side of the trail, making for good snacking opportunities in late summer and early fall.

Looking down American River Valley from Chinook Pass

Trail from Chinook Pass

After a mile, the trail made a sharp left turn and entered the forest, climbing gently over the course of the next three-quarters of a mile to reach Sheep Lake, about 1.8 miles from the trailhead. This is a small, pretty lake ringed by slightly rocky ridges that is quite popular with day hikers. The trail wrapped around the eastern end of the lake, crossing the lake's outlet stream. After passing the outlet, a side trail broke off to the left and followed the lakeshore to a set of campsites on the lake's far end. There is an excellent huckleberry patch back here, brimming with fat and delicious blue Cascade huckleberries, the prized Vaccinium deliciosum. This berry's sweet and intense flavor is a favorite of bears, humans, and other mountain residents at the end of summer.

Sheep Lake

Returning to the trail, we followed the PCT beyond Sheep Lake, ascending at a moderate grade through a patchwork of meadows and forest. A few final wildflowers were still blooming in the meadows, but I imagine that during the peak wildflower bloom in July and early August there would've been quite a show here. After making a sharp switchback and swinging west, grand views opened to the south. Sheep Lake lay in the basin below, with Naches Peak and Yakima Peak rising above Chinook Pass beyond that. In the distance, Mount Adams and Mount St. Helens rose out of the many forested layers of ridges of the southern Cascades.

Sheep Lake and Mount Adams

The trail reached Sourdough Gap a mile after leaving Sheep Lake. Passing through the gap, we entered the Morse Creek drainage, with decent views of the valley and the ridge bounding the valley to the north. Here, the PCT began to descend slightly through fields of huckleberry, meeting the Crystal Lake Trail at the end of its first switchback. While the PCT continued switchbacking and dropping downhill, we followed the Crystal Lake Trail instead, which continued cutting across a mountain slope to reach an unnamed saddle. Crossing the saddle, we entered the Crystal Lake basin in Mount Rainier National Park. Crystal Peak and the Palisades came into view.

Entering the Crystal Lake basin

The trail descended slightly upon entering the basin through meadows that were past peak bloom but that were still filled with western anemone seedheads. The sharp peak that rises over Sourdough Gap looked particularly dramatic from this angle, adding interest to the scenery.

Western Anemone

Following the trail just a bit farther, we came to a beautiful view of Mount Rainier and Crystal Lake. Crystal Lake's glittering waters filled the basin below, with Crystal Peak rising above. Rainier rose above the shoulder of Crystal Peak, crowned on this summer day with a lenticular cloud. This angle provided a direct view of Rainier's east face, dominated by the massive Emmons Glacier, which is the largest glacier in the contiguous United States. From this angle, Little Tahoma blended into the mountain itself. Rocky features bound the Emmons and Winthrop Glaciers on both sides: Gibraltar Rock and Disappointment Cleaver to the south, the Willis Wall to the north.

Mount Rainier rises above Crystal Lake

There's no formal turnaround point for this hike. The Crystal Lake Trail offered good views as it crossed the high slopes of the basin near the saddle; we stopped at a point with a clear view of the lake and turned around before the trail made a wide bend to descend towards the lake below.

This was a popular and easy but enjoyable hike with nice views. While not a showstopper, it's a nice way to see some pretty scenery near Rainier while exploring a short, easy stretch of the PCT.