As I gathered my wits, I heard a noise in the brush, and watched as a HUMONGOUS MAMA BEAR ambled out to sit under the tree the baby bear had fled to. I looked at her. She looked at me. I wasn't exactly frightened, as she seemed more irked with the antics of the little bear than she seemed upset about me. The cub made some funny kind of mewling noises, and then the mama bear looked up at him and made what I can only term as an "exasperated sigh" at which he backed down the tree, far more slowly than he had gone up it, and they ambled away down the trail toward the shelter.
After sitting in awe for several minutes, I got up and went down to the shelter, but nobody else had seen the bears. I later read through the shelter log, and apparently several others had encountered the same bears, either in walking to the shelter or in the early morning. However, no one had had any confrontations and the bears had not been aggressive towards anybody, so I think it's proof that if you do not feed them or allow them to encounter human food, black bears really aren't a threat. I will say that everyone has been doing great at following "best bear practices" from what I've seen, and I'm glad now that we're so conscientious!