Camelbak: Take The Tactical Valve Up The Mountain.

My successful of Hack McNett's Pioneer Pro Water Filter used a lot of odds and ends but it all worked on my latest trek.

(As an aside, McNett tells me that their product development "skunk works" has taken my hack to heart and is developing a new product like it.)

Anyway, when I hurried to put together a trek up to the John Muir Wilderness area west of Bishop, CA, I forgot something very important.

Campsite next to Hungry Packer Lake, little over 11,000 ft in John Muir Wilderness

 Last weekend, I was hustling to get up to the Sierra in front of an approaching, early-fall snow storm, so I threw my go-pack together (along with the hacked McNett), hopped in my trusty Silverado 2500HD 4x4 for the seven-hour trip to a trailhead, looking for an easy trek up to Hungry Packer Lake (about 11,000 feet).

As expected, it dropped to about 20 degrees -- balmy compared to the way-below-zero temps on my winter mountaineering treks ... but still cold enough to sleep with the Camelbak insde my sleeping bag to keep it (and my clean water) from freezing.

Only problem is that I had left my low-land, running valve on the drink tube (below):

And at altitude, and with the slightest pressure (like turning over in my sleeping bag) it will drip. Very slowly. But leak it it will. And the tea saucer-sized wet spot was highly unpleasant at 2 a.m.

Fortunately, my below-zero-rated bag is synthetic fill and my long-johns wick away moisture. I still needed water, so stuck the valve in a Zip-Loc and went back to sleep.

I stuck my usual valve (below) on as soon as I got home.