Is it possible that the lake is merely a cover for a large underground facility? How big is the lake anyway?

This is interesting, I'm going to have to do some Area 51 research.

It's about 3 miles across from north to south. Some of the items seen in the photo include an oval shaped dark area called Slater Lake, arrayed around it are several radar installations which provide an insight on how foreign radars will fare against current and new stealth aircraft. The area seen on the lakebed was a dismantled radar test range item, as was the oval shaped area with the circle above it also on the lake east of Slater Lake. That was a hydraulically raised RCS pylon built for A-12 testing in the early 60's. By the base itself the control tower is highlighted. Not sure what's on the mountain, although there is to the south on one of the mountains a radio station.