It's a little past your desired range, but last year I spent a few days on Kanopolis Lake near Marquette, KS. There's a State Park there with decent facilities and a federal campground on the other side of the lake. There was virtually no one there. I expect the lake is down due to the lack of rain, but you can no doubt check online or call and ask. There used to be trout fishing in the dam's tailwaters ...
IIRC, there are electric hookups both places, but I'm not totally sure about that. It's pretty much in the middle of nowhere.