It gets its nutrients from other plants such as lanceleaf stonecrop Sedum lanceolatum, which were plentiful in the area.
The stonecrop doesn't look that tasty to me, but Wikipedia says the leaves of all stonecrops store water and are edible. Hmm, I learn something new every day.
On the same hike, we ran across this carving on an aspen tree:
1844? Is that possible? A mountain man might have been here then. That's about it. The other question is whether an aspen tree could live that long. I read that they can live about 150 years, so the date is a little bit of a stretch, tree-wise.
Assuming the carver wasn't being purposefully deceptive, maybe it's 1944, distorted by time. Yes, that's more likely. But who the heck is K.B.?