Bad Medicine lake? Sounds like it, man. I’d pour out some extra tobacco before going on THAT water! Don’t wanna mess those water spirits, I tell ya.
Per the Bad medicine lake wiki:
It got its name from the fact that early Native Americans in the area thought that a lake with neither inlet nor outlet was a place of bad omen (“bad medicine”) and would not hunt or fish near the lake.
Personally I absolutely love the lake. 32ft visibility gives it a neat aqua green/blue color. Plus the fishing is spectacular.