RVTW interconnects with campgroundreviews.com, but even Campground Reviews does not know which campgrounds of over 20,000 can be booked online.
Generally,I plan a route where I
, want to stop using filters for memberships, hookups, amenities, etc. and check reviews. Then I follow the link to the CG's website to make a reservation whether online or email or by phone.
Many nice reasonably priced CGs for one night don't have online reservation capability. I know of a 4-5 that don't have online capability, even so, they usually have way to request a reservation via email. A few that we've stayed at don't even require a deposit with a phone call. More and more are automating. One particular favorite CG recently added ability to reserve online.
Of course, KOA CG's can all be booked thru the KOA website. All US Govt National Parks, National Forests, Corp of Engineers, Bureau of Land Management Parks are booked thru www.recreation.gov
. Many state & county parks are booked thru www.reserveamerica.com