tarp vs bivy on HST

nm

Hi Gustav! If you'll be spending a lot of time in wet, humid conditions or if nighttime temperatures drop down to the dew point, then the waterproof-breathable type bivy loses some of its breathability, which means condensation inside. This should not be of great concern for a short 2-3 day trip, but for a trip of longer duration the down bag will require daily drying out in the sun; if this is not possible then the down will start to clump together and thus will not insulate. Not the most desirable outcome!

What I do to avoid wetting out my down bag is to add a vapor barrior liner. This keeps the humidity exuded by your skin out of the down and thus keeps it dry. A lot of folks at first think this arrangement must be terribly uncomfortable, but not so. After a certain level of humidity is attained the skin ceases to respire and there's no problem with condensation inside the liner. As a bonus the liner adds about 10F to the bag.

An even better approach is to team a tarp with a water repellant-breathable bivy. They're lighter – around 6 oz – and they breath so well that you could dispense with the VB liner, though in continually wet conditions I would still use it.

Happy trails!

Sounds to me like you could use an Integral Designs eVENT Unishelter – basically a hooped bivy of fully waterproof and highly breathable fabric. Heavy, but eliminates the need for a tarp if used carefully.

I've hiked the HST out and back in 2003. You will probably only camp in one place that is above treeline; Crabtree. Hamilton lakes is close, but the camping there is among a few trees.

With that in mind, I would just grab a stick along the trail and use the tarp. Just be sure to grab it before you get into camp.

Have fun! It is a great hike. It has hotsprings and plenty of pit toilets (hard to believe, but I only had to dig a hole once)

Steve

Thank you all for your thoughtful replies. I think I will take the tarp and continue to hone my tarp skills.