The ACA did set up some discount rates for members at certain nice RV parks along their routes, but the inland Oregon and California State Parks very often have dedicated hiker-biker sites, not just the coastal parks. You can also check out fairgrounds and county parks, which may have very nice campsites at good rates, yet can be quite unknown outside of locals.
I'm familiar with some of the inland California parks--do you have a route set yet? If it's the coast route, you should be able to do the whole route without ever staying at an RV park, though the Manchester KOA is a lot nicer than the state park.
Last edited by stevepusser; 11-19-19 at 11:22 PM.