Granted, a few folks here have heavily modded their Trac for some serious trail use, but really the ST is not designed for that. The turning radius is too wide for jeep trail use in Colorado.
"Trail-rated" refers to Jeep's testing on the Rubicon trail. An ST can be modded to take on this trail, but only a few have spent the time and money to do it. Search for Johnstone or Thrandur Arnthorsson to see a couple of heavily modded STs which may be able to take on the Rubicon trail.
The vehicles I see headed up to Loon lake and the trailhead for the Jeepers Jamboree are modified Jeep CJ-5's and 7's. Maybe on Jereps are invited, but I believe our ST's have too long of a wheelbase to make it up the trail.
Can be done, but that long wheelbase hurts you. I believe that pic of Johnstone was taken at Rubicon. FWIW he's got a mess of lift and a front locker. You can off-road, just have to watch the breakovers because of the long wheelbase, but I've climbed hills so steep that all you could see out the windshield was sky.