Filtering Drinking Water
This was probably the best spring we found in the col. I was a bit shocked not to find another or a better one, but the water here was plentiful, if not a bit hard to access.
I learned a long time ago carrying a portable filter was a lot lighter than carrying water, and the time it takes to refill your bottles and water bladders is offset by the fact you can hike faster with less weight. It's also offset by the fact you generally will drink more and conserve less. Finally, filtering vs. carrying allows you to hike much farther even on day hikes.
For more on this trip, or any of my adventures....