I'm in the Rockies, so there's not usually as much duff, but we do have some gravelly soil in places, which can be like a sieve. I should be able to find some of that.

In RMNP, the designated sites have packed, flat pads for tents. I've had water run underneath my tarp once on one of those, which has fueled my fear of the water. It was actually snowing really hard that time and I'm not sure anything would have prevented some water coming under.

Even so, I feel like I just need to get over it and try it out on a nice night to see if I like it. I sleep on an inflatable pad, so it's basically like a pool-lounger, right? I should be fine.