Oncoman, The Comstocks and I used the Little Nesowadnehunk Stream approach for Mullen back in the mid 1980s. It's a long day slog and I don't especially recommend it. We went up from the col south of the peak and returned there. We went out (up) along the cross hair "+" slope (fairly open), avoiding that sharp (dark and thick) ridge off Fort and ended up at the herd path col marked "3668 T". It was still a long trail hike out from there, but I'd still prefer that (both ways) to the stream bushwhack. You will hear from others here who have approached Mullen from the NE or E. That may well be better than what we did. Have fun!
we got to Mullen via Mullen Brook ... blue blazes mark the old path up to Mullen Pond ... from there, it's kinda thick getting up to the summit, but worth it ! nice trip from Russell Pond
we went from OJI > Barren > Owl ... not bad, following open swaths through Klondike, until we were due north of Barren, thick whack uphill from there
the ridge down from Barren to the Barren-Owl col wasn't bad, but it was rougher climbing Owl from the col ... thick spruce hiding horizontal thigh-high dead trees ... a friend later told us it's supposed to be easier in that col if you stay towards the south side of the col, losing a bit more elevation in favor of more open woods
would like to try that slide on the south side of Barren someday
Saw your name in the hiker log at Katahdin stream on Sat. Morning. Was 3 hours behind you going up the Owl. Looked over toward Barren a lot but didn't see any trees moving.
I'm sure you enjoyed the slide it's a blast!