Back when I was hiking in the ’60’s and ’70’s, we just drank water out of streams and lakes if they seemed like they were ‘safe’. We looked for running water, especially if it had enough of a drop to it to get aerated. We figured the oxygen cleaned it up. I had friends that kept that philosophy up through the ’90’s. I started filtering water much earlier than that … about the first that backpacking filters became available. These photos are both taken at Heart Lake in the upper Sol Duc valley in the Olympic National Park. The photo below shows how the lake got its name.