Unfortunately, its very popularity caused its pollution by tons of lead shot, which in time, killed the water fowl that made the lake so popular. Similar studies could be done for other lakes, involving looking for lead sinkers as well as for lead shot. To the geologist, this demonstrates the old principle that small scale processes can have big effects over time. One or two shotgun blasts over a lake don't have much effect. It also shows how the value of mineral commodities change.
Lead mines are a depressed industry.