I decided to get an afternoon hike in this afternoon, post my failed Mount Hood attempt two days ago, and Humpback Mountain has been on my list, as with some other South I90 peaks to the East of McClellan Butte.
This is a tail of three trails. I took the northernmost and shorter access point to the logging road 5510-120 and entered the hiking trail as it rounds the bend. The initial part of the trail is rough raw dirt and looks recently excavated. Once above this section, the trail climbs steeply through dense forest – seems it’s been logged multiple times, and the trees are very thin, dense, and little light gets through this.
I pushed on and connected to the other logging trail access point up 5510-110, and continued upward. Again the trail is steep, lots of roots and fallen logs (all passable) just need to be careful with the footwork as the logs are slippery when wet. The trail is all dry dirt, carpeted in Douglass Fir needles. About a third of the way up this section, the forest canopy opens up and there are much larger trees spaced apart and a very interesting forest floor covered in young Douglass Fir trees ranging from 4′ to 6′ in height. Almost as if this were some special Fir garden.
The trail continues up steeply, but the grade lessens around 4000 feet. From here I encountered numerous talus fields and large boulders. This section of trail is quite beautiful, in fact, one of the most enjoyable trails I have hiked in a while. The trails follows the ridge, which becomes steep on the East side, the West side flanked by long talus fields. As the trail climbs to the summit, the small firs, boulders, and other plant make it seem like some natural Bonsai garden. This is truly a beautiful trail the remainder of the way up.
The summit is covered in large boulders, and the views are spectacular. I was alone at the summit of Humpback Mountain. All alone on the top and complete solitude. Amazing 360-degree views of everything. Rainier. McClellan. Silver, Tinkham, Abiel. Granite. Kaleetan. Snoqualmie. Guye. Thompson. Lemah. HiBox. Stuart. Caroline. Too many to list. I found the initial part of the trail a bit challenging until I warmed up. Expect some scrambling over rock and trees, but the upper section of the trail and views are so worth it – this is much better than most if not all of the hikes earlier than I90 milepost 47.