In a normal year you would still find lots of males guarding eggs or fry in the clear water. This year who knows...................but I think the big girls will be mostly deeper, resting from the spawn. The beauty of the Rock is that in May, you can catch pre-spawn, spawn, and post spawn all at the same time, depending what part of the lake you are fishing.
My advice to you, would be to hire Babler or Beck for a day, it will be the best money that you ever spent.