Re: mountain water purity. I once saw a study referred to on this or a similar forum. Water was sampled from multiple Sierra lakes and streams. The test results showed that in almost every case, the untreated mountain water was cleaner and more pure than most municipal water sources. The contaminated water supply in Flint, MI, a couple of years ago is a great example of how our trust in what comes out of our taps is not always warranted. As many experienced hikers do, I almost always drink straight from the lake or stream, unfiltered, and can't recall a case where I paid a price. Of course, one must be smart about what's upstream...
