Well, we made it back alive. Bennett Pass Rd/NF-3550 is a single lane (which serves both directions) dirt track.
We had spent the night at Rock Creek CG and thus driving up NF-4860 to the turn at the intersection with NF-3550. There are, however, only 1 or 2 places to turn around after that. We had to digg (a 4-letter word) through 2 snow banks to gain passage and only saw one other vehicle (a Jeep) on the route. High clearance 4x4 vehicle required on NF-3550.
The hike itself was fantastic, once we found a place close enough to hop on the Gunsight Trail #685 which goes past the top. Note that this means the trail doesn't actually go to the summit so you will need to bushwack the last 200' or so uphill to the summit. There are 2 rock piles that make convenient operating positions and plenty of trees to attach a mast or throw a line.
If I go up there again, I will park at Camp Windy and do the whole hike, avoiding NF-3550.
Cell coverage was not good enough to do a spot. I didn't try calling anyone. However, 20m was alive and well and I made 12 QSOs in short order.
After the activation, I decided to drive on rather than face the snow banks again. There are a few pretty washed out sections after that which took some careful maneuvering to get through. It eventually pops out on Lookout Mountain Rd which I'm told is an easy activation hike to W7O/CN-008. However, by that point, we were tired from all the excitement of getting back to a main road and decided to leave that for another day.
Bennett Pass Road will definitely test your 4x4 high-clearance vehicle and your nerves.
Note also that (in 2021) there is a road closure for NF-48 and detour which takes you around the forest fire burnt section.
