Great question — answering as the UphillTech team:
Liability is the biggest concern. You should have like an LLC to reduce the risk of sued personally. You should have lawyer draft a waiver that will (hopefully) stand up in court. Insurance. Another concern is customer satisfaction. A new backpacker that has no experience is not likely to have a good experience. An experienced backpacker waiting on a beginner is not going to have a good experience. You can have partner that allows for a split but that is more cost. You need to have something unique or rare: If it is a secluded water fall it is only secret until the first trip with GPS. A climbing guide would work if routes are hard to know / find. If you have a license they cannot easily...
Full answer by paparazzo: https://outdoors.stackexchange.com/a/20744 (CC BY-SA 4.0).
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