I think that you are right about the winter kill off up there. Based upon a report from my next door neighbor (who fished two or three times a week until about 8 years ago - since they he only goes about 3 times a year), I had a buddy of my check it out. Need-less-to-say, he didn't stay long. He only caught three in a couple of hours and none of them were worth bragging about. At one time though Treasureton was one of the best.