Before you lose all faith in your fellow climbers keep in mind that marmots can and do make off with people's gear and it's surprising how much they can drag off. They love to chew on the salts from your skin that build up on gear. Also seen mountain goats messing around with gear but not sure if they actually drag stuff off.

Either stop stashing stuff or get better at it. Then you won't have to be all melodramatic about blaming 'fellow climbers' for being forced to drink water borne pathogens or whatever it is you're claiming.

Or they were considered trash like they should be. You know what I do when I see water bottles littering the trail like the litter they are? Dump them out out and take the bottles with me. Bring a filter or tablets next time and don't leave your stuff all over the place unattended.

Welcome to crowded Colorado. Sure was cooler before it became the cool place for people to move to.

Cleaning trash off the trail is an act of good citizenship. Littering in the wilderness is destroying my faith in humanity.

Filters weigh barely anything and the newer ones are super quick. For how hot it is this time of year, there's no reason not to bring one in case you run out of water

Lighten up people! It is clear that a $100 filter bottle plus a normal water bottle that were left on top of a rock so they could be found later on were not litter! I am far from the only person to ever strategically stash a piece of equipment and then retrieve it a few hours later. This was an eerily empty valley and we had not seen any sign of another person up to that point.

I would expect that the average person should be able to discern between a discarded empty bottle (or even one randomly dropped on a trail) and a pair of full bottles placed together on top of a rock. With hindsight it is clear that I need to be more careful as to where I leave a bottle, but I am certainly not a litterer. I also suggest that it could be quite dangerous to remove another person's critical gear when you aren't certain of the circumstances.

Ps, I did consider that animals may have taken them but after a thorough search of the area and further thought, we decided that they were not attractive to an animal since a plastic bottle isn't going to absorb sweat. Plus they would be quite awkward for a small animal to carry across scree! It's a bit like an African swallow carrying a coconut by its husk. It's a simple question of weight ratios.