Carmichael pointed to a tree that fell across one of the riverside campground spots, taking out a fence. There’s another on the opposite side of the path, branches strewn across an open patch of snow. They’re among the 1,000 high-priority trees the city wants to remove due to safety concerns.

"The spruce bark beetle epidemic currently ravaging Southcentral AK's spruce trees is well-known, but I haven't heard mention of other pests occurring in conjunction."

The latest tally of beetle kill shows more than 550,000 acres of forest with dead spruce from the ongoing infestation this year alone, much of it in Mat-Su.

Beetles that killed millions of acres of trees in the 1990s were a first sign of climate change. In a new flare-up, they continue marching north as Alaska warms.