Algae Bloom Turns Boise River Into "Unfishable" Slime

Published Jul 25, 2026, 9:50 PM
  • Local angler Chandler Bondurant reports that persistent brown globs are clogging fishing lines throughout the city.
  • The buildup of mysterious river slime has hindered daily fly-fishing efforts since early July.

Chandler Bondurant, a dedicated local fly-fisher, has hit a frustrating wall in his daily routine on the Boise River. Since the first week of July, the river has been plagued by an influx of slimy, brown debris that attaches to fishing gear upon every cast.

“It’s pretty much unfishable in town,” Bondurant shared in an interview with the Idaho Statesman. Describing the persistent conditions, he noted that the river is filled with consistent floating gunk that snags on hooks and knots, making the activity nearly impossible. “If you are standing in the river and you pay attention, you’ll see that there are little pieces of gunk just consistently floating through, and it doesn’t stop,” he added.

This issue has raised concerns among the local angling community regarding the health and accessibility of the river during the peak summer season.

  • Boise River
  • Fly-fishing
  • Environmental Concerns
  • Idaho Outdoors
  • Water Quality