What parts of Idaho are you looking to travel in? All the state parks are great to visit. The Fall is a great time to travel because there are fewer other travelers and sites are usually plenty. What was mentioned in the first reply is South Central Idaho and is beautiful. There are lots of dry campgrounds and fewer with hookups in the mountains. There is a very nice little full hookup RV park on Hwy 75 between Stanley and Clayton called
Torrey's Burnt Creek Inn. It's a great place to use as a base camp to visit the historic Sunbeam Dam and the road (there at the dam) to the ghost towns of Custer, Bonanza, and the historic Gold Fork Dredge. At Sunbeam Dam is Sunbeam Hot Springs, free to use at the Salmon River's edge, just go with your suits on. Cascade Lake State Park has several campgrounds around the lake with hookups and only one has full hookups - Poison Creek. All can be reserved online or if you go midweek, chances are pretty good to get a spot. At Three Island Crossing State Park is the Oregon Trail Interpretive Center. This state park has full hookups. Bruneau Dunes State Park is at a natural sand dunes and they have an observatory that runs on a schedule. In Eastern Idaho is the Yellowstone Caldera and there resides Upper and Lower Mesa Falls. There are many campgrounds in that area with hookups. Our favorite is at Lower Mesa Falls called Grand View. Water and electric hookups and really nice. You hear the roar of the falls constantly. Visit too while in the Island Park area, Johnny Sack's Cabin, Big Springs, Henry's Lake - there's a state park here too, Harriman State Park, Quake Lake, and of course this is close to West Yellowstone. We've been all over the state and there's so much to mention. We recently traveled northern Idaho last Fall and stayed at Farragut State Park and toured it. Farragut was one of the largest inland Naval stations in the US. What a fascinating place that was and the state park for camping is fabulous. Full hookups. Definitely a return trip for us. We also stated at Hells Gate State Park in Lewiston on the Lewiston River. Nice, but not as nice as Farragut. Idaho is a large area, so you may want to pick the region you plan to visit and ask your questions again.
Island Park Area InformationIdaho State Parks InformationVisit Idaho GuideWhile in the Stanley area, plan to take the Landmark Stanley Road (Middle Form of the Salmon River road)over Cape Horn Summit, down into Bruce Meadows to see the herds of elk that live there. Best time to view the elk are early in the morning or at dusk. We pack our breakfast and head over there early and sit in our truck to view the elk. It's never a boring moment.
If you can handle one or two nights of dry camping, spend some time at Bull Trout Lake Campground in the Martin Lake section, you may just be rewarded with the howl of a wolf as we've been.