I haven't camped there, but I stopped for lunch once at a campsite at the NW corner of the lake.  It's the one to the south of the inlet leading to the portage to Hatchet Lake.  My trip report describes it as a "moonscape."  You might not want to base camp there.

This map
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shows good campsites as circled.  I don't have any information about the ones on Thomas, but the circled ones are where I'd look first.