From the North Lake TH, take the Piute Pass Trail to the top of Piute Pass (5.4 miles from the parking lot). You can see Mt. Humphreys to the north from here. Go cross-country across Humpheys Basin to the highest of the Humphreys Lakes (3.2 miles). This is the last place you'll be able to get water if you need it. The Humphreys Basin has lots of ups and downs, mostly minor. Outbound route-finding is easy if you just keep Mt. Humphreys' summit in front of you. Take a moment to find Muriel Peak behind you. This is your marker for the return, which is harder if you don't remember this. At the lake, Mt. Humphreys' massive SW slope now stands before you. Get there early and you can enjoy climbing in the shade on hot summer days.
There is an obvious wide gully halfway up the peak that slopes up and left to the notch NW of the summit. Reaching this gully is your first objective. There are many ways including face climbing or taking one of several chutes to reach the wide gully. The easiest is probably the widest chute on the far left (NW) side of the slope. This chute is almost all class 2. There is a large obstruction about 1/3 of the way up. This can be climbed in several ways: class 3 narrow ledges on the left side, or some class 3 climbing right up the center. Try it, it's fun! Or you can keep going with class 2 by climbing out of the chute to the left via another steep, loose chute.
Once in the wide gully, it is easy but tedious loose class 2 to the NW notch. Once at the notch, take a moment to enjoy the view down the North Couloir Direct on the other side. Looking up towards the summit, the next section follows a narrower gully, or trough, just to the right of the NW ridge's spine. This section is rated class 3. At the end of the trough you will find yourself in a small pocket, further progress ahead blocked by a headwall. There may be rappel slings here. Don't panic, it's not that hard.
Next, move out of the pocket to the right (west) on some very easy class 4 ledges. Enjoy the moment, as it is short and sweet (like about 15 seconds worth). Remember your excellent holds for the return. Climb up another 40 feet or so to the next class 4 section. This one is steeper and longer (maybe 30 feet), but the holds are even better. You may see some more rappel slings. Bask in the glory of poo-pooing the need for a rope. But again, remember your holds. Once above here, it is easy class 2-3 climbing to the summit. This part is also very fun.
No rope necessary, though many parties rope up for the class 4 sections. They are easy class 4, though. If you are comfortable on class 3 climbing, this is an excellent introductory route for class 4 soloing.
If you have information about this route that doesn't pertain to any of the other sections, please add it here.