Boondockers Welcome is a site that allows people to guest stay at Host site locations for a few days in their RVs. Some locations provide services for a fee and some provides some services for nothing. One location that we stayed at for example had 30 amp electrical and water for free and would not even accept a donation. For $50 a year, it has certainly paid for itself already.

https://www.boondockerswelcome.com/