Noble knob is the site of a former fire lookout. There appear to be a couple of ways to access Noble Knob from Hwy 410 heading towards Mt Rainier National Park. We took Corral Pass Rd just south of the Alta Crystal Resort. This becomes the 6.4 mile, very crappy forest road to the trail head. There's a sign at the beginning stating that the road is for experienced mountain drivers only. If you aren't experienced when you start, you will be by the time you finish...
There's a nice parking area at the top for Corral Pass with picnic tables, camp sites and a privy. The Noble Knob trail head is up the road from here with it's own parking and picnic table. Don't be fooled by the info sign at a trail head across from the parking area. I'm not sure where this goes.
Walk to the picnic table and the trail starts there. We only saw a few other groups along the way because we started late in the day. Two mountain bikers were also up there. It looks like a great location for that.
There are only a couple of stretches that will get you out of breath. For the most part it is a moderate hike. The views from the top are amazing. We also saw a family of mountain goats north of the knob about 100 yards away.
Views of Mt Rainier are going to be best in the AM. We had the sun in our face looking in that direction, but that mountain is beautiful from any angle at any time. There's one trick part of the trail to note. At one point there's a sharp hairpin turn with a sign at the apex but no mention of the Noble Knob trail. You need to take the unmarked trail going north. I'll post a photo for reference.
Map & Stats
6.5 mi out & back
669 ft elev gain (the forest road takes you most of the way up)
No pass required