[Trapped Behind Enemy Lines]

Could not all of come from humans. Not THAT many have climbed the mountain. Perhaps a lot of Yetis running around up there.

[KarlInOhio]

They say hundreds per year stay at the base camps for weeks. Even at a minimum lets say 200 for 2 weeks and a pound a day each. That's almost a ton and a half every year minimum. Multiply that by 50 years since Hillary Clinton's namesake first climbed Everest and you get a lot of poop.