These are horrible pictures. I made Jason go back to the site with me to get a few shots for proof! I looked up some bear facts before returning, and learned a hibernating bear can completely wake up in 2-8 minutes! So we snapped a few and when he started lifting his head, we knew it was time to leave.
I learned it was likely a male, sleeping on top of the ground in the open. The males will sometimes just stop and hibernated where ever they are at the time, and females commonly return to a den annually. He had a good location, with such noisy grass and closely grown brush. Anything going by or coming close would alarm him.
Bears can go 100 days without eating or drinking. It's temperature drops roughly 12 degrees to about 88F. Their heartbeat drops from 40-50 each minute to only 8 when in the deepest sleep.