gymnastics not optional
I still have fond memories of my 18 hour day with Mark Lowell climbing Allen from the east back in September of '00. It was during those bleak days when the future of the Allen herdpath was uncertain, so Mark and I decided to scope out a legal approach from the east. We went up the Elk Lake Marcy trail to state land then roughly contoured toward Allen, then up to the Allen-McDonnel col, then finally up the ridge to the summit. It took us about 5 hours through essentially interminable blowdown and thickets, 2 hours of much-needed recovery time on the summit (mostly to allow the painful flesh wounds to stop throbbing), 5 hours back to the trail just at full darkness, then a long slog by lamp out to the trailhead.
One technique I adopted during that ascent was to grab ahold of the upfacing limbs of a downed tree, often at head height (couldn't go under because the downfacing branches formed an inpenetrable barrier), then carefully maneuver a leg over the tree trunk, pack hanging upside down off my shoulders, and hoist myself up onto the trunk in a sitting position. Mark, having much longer legs than I, was often able to "simply" step over the tree.
If you are into adventures I highly recommend this one. You might wait for a dry day (a friend did a similar route up Allen with water soaked tree branches, which is an act of sheer determination if ever I saw one). Best if the weather is a bit cool so you can comfortable wear long sleeves and full pants. It was quite hot when Mark and I climbed it, and I wore shorts most of the way up (a major cause of my shredded flesh problem) before zipping on the legs.
An interesting aside, the Allen hike was when Mark and I found our first (and second) wilderness balloons, way up on the side of Allen in the middle of blowdown. Since then we have VERY frequently found balloons on our bushwhacks, including a fully inflated one between Big Slide and Porter in '03. Just last month Mark and I found a balloon on Kilburn one day and Sentinel the next day, then Paul Coarding and I found one on Slide Mtn (Sentinel Range) a few weeks later. There must be tens of thousands of balloons in these mountains for us to find them so frequently.