Hmmmm, Maybe you've discovered something newly created! Did you say there waz a boatlunch newly constructed on it?? There were several large (but not 200 acres) seepage ponds in that area but none had a boatlaunch on them.
May be worth investigating.

As Big Jon said there is NO Camping at Billy Clap nor anywhere nearby there. In fact the nearest I legal free campground I can think if is back at Alkali, but there is an inexpensive one at Soap lake, just as you first hit the lake going out of town.

The fishing on Billy Clap is a highly guarded secret and mostly hit by locals.
It is fair for Walleye,excellent for Smallmouth,and better than Average for trout though not as good as the plant would lead on to believe ,cause they plant fry and the walleye and bass eat half or more of them.