This is another Bitterroot trail that's not for the faint of heart. There are hills to push your bike up, steep sections you might want to walk your bike down, sections of trail
become faint or even disappear, trees need to be climbed over, and there's no easy way out if you get in over your head.
Start by riding what you can and pushing when you must to get up to the ridge over to Skalkaho Mountain. There's an old illegal ATV trail to the top you can push your bike up along, or you can try and imagine a trail to the saddle just to the east of the summit.
Either way, head to the pinnacle for some great views, then drop back down to the saddle and try and find the entrance to the trail through the cliff bands. Ride this trail until it disappears, and make your way down steep game trails until you might find the trail heading north (rider's left) towards the bottom of the basin.
For the next several miles, the trail does its Cheshire Cat disappearing act. In general, the trail sidehills along a northward trending ridge before dropping into a small pond. Skirt the Pond and climb into the trees and into a burn just before rendezvousing with Alternate Palisades Trail #44
I suppose you could drive Butterfly Road #364
to the trail and do an out-and-back to the top of Skalkaho Mountain. It would be a fun descent on the way back, but it would also end up being a lot of road for not much trail.
If you've read the rest of the description and are intrigued, I would suggest starting at the bottom of Butterfly Road and climbing the road, riding the trail, and then finishing a big all-day loop with Alternate Palisades Trail #44
, Upper Palisades Trail #44 and Willow Creek.