Last year, the Flathead Watershed and its five tributaries were so choked with snowmelt and spring moisture that Flathead Lake overfilled naturally for the first time since 1964, when historic floods devastated local communities and reset the record books. This year, dam operators responsible for controlling the outflow of Flathead Lake began refilling the basin a full six weeks early, desperately trying to capture the region’s scant mountain runoff as forecasts showed lake levels dropping to historic lows.