In all, the cluster that totaled five distinct glaciers, covering about 1.5 square miles back in 1984, has shrunk down to patches of ice less than one-third of a square mile. Nearby Overcoat Glacier, also in King County, is in the same throes.

"Only Lynch Glacier remains an active glacier," he said. "That one still has a chance to sustain itself for a time. It's effectively the last functional glacier left in King County, flowing west toward Puget Sound."

That last part is crucial. The Skykomish River below these peaks is already on a federal watch list for higher-than-healthy water temperatures. Pelto observed that the recommended max temperature of the river water for salmon, about 60 degrees, has been exceeded every day this summer since late July.

"The loss of the ice up there is causing issues that extend all the way to the Sound," he said.