Ironically, the problem in this case is that cash requires too much trust; trust that local deposits won't be raided by thieves.
A more "trustless" approach could involve the collection box being replaced by a link or QR code or a bunch of detachable paper slips with said link. Link leads to online donation portal. Of course, someone could try to tamper with those links.
Switzerland has a national payment network called Twint, created by the Post, that’s based on QR codes. I think the bigger challenge is getting cell coverage to all of these remote peaks.
but you don't actually need cell service on the hill, do you? there's no payment enforcement anyways, so you can just record the bill and submit the payment once you have service.
Switzerland already have QR code based payment (twint, can debit directly from your credit card). Bunch of self service farm products simply have the qr code.
It's also common to have qr-code or cash only payment available in mountain restaurants.
(or even in other venues, was surprised to have a large festival in Zurich which was mostly qr-code or cash).
So what do yo do when the AZ you are in is down? You use cash. Remember what happened in Hawaii this summer? Don't take anything for granted. It mostly works but what do you do when it doesn't?
A more "trustless" approach could involve the collection box being replaced by a link or QR code or a bunch of detachable paper slips with said link. Link leads to online donation portal. Of course, someone could try to tamper with those links.