The most brazen marmot I've ever seen wasn't around Whitney but rather on the slopes up to Wheeler Peak, the NM state highpoint. If you scroll about halfway down in
this page, there is a nice shot of our "friend."
Whenever Nathan and I would stop (between 11,000' at Williams Lake and 13,000' at the summit ridge) to catch our breath, this guy would be right there, begging for a handout. He would actually walk (waddle is more like it...he was pretty well fed) up and put his front paws on our boots and look up at us.
He finally departed in a
big hurry when he crossed from his territory into that of a much bigger marmot about 100 yards farther uphill. The big guy chased him all the way out of sight and that was the last we saw of either of them.
The golden-mantled ground squirrels back down at Williams Lake were similarly bold...they would actually sit there and
complain at you if you stopped and didn't feed them.
That said, I've never had a problem with the two-legged critters taking anything from my campsites either in the Sierra, Rockies or elsewhere. Mostly, I figure if I'm a good day's walk from the nearest trailhead, the other people there are generally pretty good folk. I make sure anything that
looks valuable is either with me or hidden inside the tent. I figure it keeps the honest people out...and the dishonest ones (as observed elsewhere in this thread) are too darned lazy to hike up there on the off chance they might score something out of a campsite.