I just got back last night from hiking this entire section (Hwy A to Hwy 21/Claybaugh Creek TH) over the last four days.
I think we may need to park at Taum Sauk Mt. instead of the Russell Mt. TH.
Parts of the trail are very rugged, I did 10 miles each day and it was tough. I think we'd be really pushing it to do 36 in 3 days.
If we do Hwy A to Taum Sauk, we're still looking at 30 miles in 3 days, and I think that will be more manageable and enjoyable. It also works out better for where I want to camp each night...otherwise we'd have too many miles on the last day.
There is a nice parking lot at Taum Sauk Mt, so we can meet there Friday morning, then cram into a couple cars and head to the Hwy A TH. We'll still be on track to meet guys at the Shut Ins on Saturday for Lunch. I scouted some great spots to camp each night! Should be fun!
With beauty all around you, may you walk.