Wow. This happened to me on our driveway the winter of '08 (over 300 feet long, and extremely steep, but gravel).
It wasn't with the Silverado but driving our old 4-door Chevy Tracker (with locking hubs). Our driveway was partially iced up, with patches of gravel protruding, but no trees nearby. The truck had to be brought down, as we were expecting 2 days of incessant freezing rains, and a rapid deep-freeze (with no chance of melt for at least 3 weeks).
I walked the driveway and picked a track, and In 4x4 low, I slid and cutched the truck down about 80 feet successfully, then It appears the 3 tires rode over ice at the same time on a 36% grade section (driveway is a raised bed). I did a slow 360 and recovered; drove another ~30 feet, then did two 360s in succession, but recovered. T'was a close one.
From that time onward, we have condemned our driveway over winters, and only plow the bottom ~70 feet.
Glad you were not injured!
