I attained the summit with my 14-year-old son, who's not much of a hiker, but he did fairly well on this hike. The road to UM Pass is in AWFUL condition. I drove it in a Ford Taurus in 2011 with only a little difficulty. This time I was in a 4WD Ford F-250 truck and it was very slow-going. Erosion has removed much of the surface dirt, leaving mostly rocks in the road. From UM Pass, we followed a route similar to that described by ZeeJay. First up an old logging road, where wild raspberries were EVERYWHERE! They were ripe and mostly sweet, and a welcome distraction for my kid. :) At about 10,800' we left the logging road and headed cross-country to the southwest until reaching the base of the steep talus that surrounds the summit ridge.
From there, we headed mostly south and tried staying on relatively flat terrain, though it was either a boulder-hop or bushwhack much of the way. I chose the saddle that's 0.17 miles (900 feet) south of the summit in order to gain the summit ridge. It was a rough but thankfully short climb, with some loose rock near the top.
We reached the saddle and crossed just over to the west side, then turned north, staying below the very top layer of cliffs. The way wasn't clear at first, but after the first few hundred feet there was a faint trail for most of the rest of the route. We continued north and circled around the very north side of the summit ridge, then found an easy place to climb up the summit block on its northeast side. There were good hand- and footholds and little exposure.
The summit logs in the mailbox were super interesting. One, placed by the Sierra Club, had names and dates going back to the mid-1960s, many of them from California. Weird.
I was partially elated at having gained the summit, but still worried about the tedious boulder-hopping that lie ahead. One see-sawing boulder and one of us could end up with a twisted ankle or a broken arm from trying to catch the fall. I was relieved when we reached the logging road again! We picked more raspberries, even bringing some back to our camp along UM Creek for my wife and older son.
We started from UM Pass and followed some old logging roads to about 10920, then traversed under the summit on the east side on some faint trails. We attained the ridge at the second little saddle south of the summit. From there, we switched to the west side where there was almost a trail underneath the cliffs until just south of the summit, but north of the first saddle and scrambled to the top.
Camped at UM Pass. Decided to climb from the NE, instead of the normal northwest approach, just to make things interesting. After slogging through some of the loosest scree I've ever encountered, I attempted a class 3-4 line I'd scouted out the day before. Would have been no problem, but the rock was far too cracked and rotten. About 30 yards up the cockscomb, I decided to turn back. Perhaps I'll return to do Martin's Ladder (the "normal" route) at some point...
My brother-in-law and I drove the 4WD jeep road to UM Pass. The road to UM Pass was not too bad except for the occasional cow in the middle of the road and deep ruts. The pass was littered with recently cut and fallen trees. It appears that the north flank of Mt. Marvine has been open to lumber companies. The area was very deforested which made for easy routefinding to the NE boulder field. Crossed the eastern boulder field and attained the summit ridge at the south end. Some Class 3 scrambling over the minor summit ridges. Summit register and mailbox were still present. Excellent hike with plenty of solitude.
August 1996 with Kimberly via more or less the North Ridge.