Mountain bikers call this trail Ice Box, but the National Park Service calls it Brandy Creek Trail
It's a river trail that is somewhat steep at the beginning but mostly a gentle descent. There are a few rocky sections, but nothing steep and rocky.
Great trail for a beginner that wants to experience some real mountain biking without committing to a long climb or lots of technical riding.
Most people ride it heading down from the trailhead off of Shasta Bally road or as part of the longer "The Chimney" ride.