Bonekrusher had the link to 157 so I took the road (about 7 miles up FR85 from the Wasatch State Park Visitor Center) he called 420. Here's the map again: http://static.stateparks.utah.gov/maps/Mill-Canyon.pdf
The sign's broken so just watch for it on the west side of the road.
1 - 2 miles up there are a couple of forks to the right that lead back into upper Snake Creek but they don't go far. The single-track link to 157 veers left up to the ridge. This is do-able on just about anything narrow with good clearance, but don't unless you're okay with riding back down. Everything beyond is steeper and rockier.
The view of Big Flat and down to Midway.
From here you can go south on 157, Past the Ant Knolls, about 3 miles along the ridge to Pole Line Pass.
Or west down the 032 connector trail into Dry Fork canyon that also drains from Sunset Peak. I only scouted this trail from either end but you'll know right away whether you want to take it. Public service announcement:!! Do not ride this trail without walking at least a couple of switch-backs first. It's extreme and I would qualify it high expert riders only! See the photo below this one.
Dry Fork is accessed on FR198 - easily ride-able on the DR650. Here's a look east at the 32 trail going from 198 (through the switch-back viewed above) to 157 on the ridge .
Don't be fooled by these sections of 32 that you can see. Walk, don't ride because there's nowhere to turn the bike around, to scout this trail. If you're too lazy or weak to walk it I don't know what else to tell you. It will be epic, and most likely unpleasant.
A look at where things split at the top of 198.
And a few views of 198 along the way.
More to follow about 157, Mineral Basin, Granite Flat and Silver Creek.