Jasper Point State Park 
Prineville Reservoir

This state park campground on Prineville reservoir is something quite rare these days.... it is first come first serve even in summer!  So if you are someone who hates planning ahead and doesn't like reservations, if you hit this one just right you might get lucky and snag a spot.  On the flip side, you also have to like to take chances, because it is quite a ways from anything else, and you might risk not getting a spot at all considering there are only 27 spots in this park.   We got lucky arriving on a Thursday evening in mid August and snagged the last available site - #26.  The sites themselves are nothing to get excited about, lack privacy, are pretty dusty, and most do not have direct water access.  However a short walk away is a large boat launch and plenty of beach to share.   We grabbed a cooler and some towels and walked the beach left from the boat launch, past the last of the campsites, and found a long stretch we had nearly to ourselves.   I would recommend it for people with boats and water toys!