

Not OP. Former NPS employee. Cairns are NOT used to mark trails in national parks. Stacking cairns in a national park is considered vandalism and you should not be doing it the same way you should not be scratching your name into goddamn rocks.
The practice of stacking cairns is so out of control I do not recommend you ever follow one on state or other lands. It is a good way to get lost following some influencer’s a.e.s.t.h.e.t.i.c pile.
The only acceptable location for a cairn is a high energy beach environment so that the sea can wipe it away in a couple of hours.
National parks are intended to be enjoyed as close to natural as possible. Leave. No. Trace.
Connect. I just like it. I tried all of the other apps available during the API exodus and settled on Connect. Functions most similarly to how I had Reddit is Fun set up.