Slate: Filtering stream water or fresh water is medically unnecessary.

Huh? Here's a counterpoint. I don't know where the author hikes, but where I do, I routinely find beavers upstream ... cow stools, dead animals lying in or near water sources ... often human stools too close to the water source. I filter ... every time. The time it takes, and the money it costs, is much less 'inconvenient' than getting sick in the backcountry. Cryptosporidium is not currently curable, and will return if your immune system is ever compromised. Sorry, not buying it. I don't care how many studies you quote. If I based my life on studies, I would be dead now. Remember when eggs were bad for you? Doctors were recommending margarine consumption for health?

Sorry, even at the highest altitudes, there's the potential to chug pika piss. Not my cup of tea.