Your asking about the Blythe launch which is west of Mardon and East of the State Park, yes there is overnight camping there. A homeless guy lives in his van at that launch. The Lind Coulee launch people camp there as well. You don't need a discover pass at either of the launches. The M road launch on the west side of the bridge I believe is a no camping launch. It has a cement launch. The east side of Rd M is a primitive launch. Memorial day weekend is a zoo at the Potholes, get there Thursday afternoon to get a decent spot to set up camp. Lots of folks camp out in the dunes. ORV park should have some pretty good parties this weekend as well.