Not uncommon for late summer, Greater Yellowstone is currently facing a surge in harmful algae blooms. Caused by an overgrowth of bacteria called cyanobacteria that has the potential to produce toxins that can sicken people, pets and wildlife, these blooms have been confirmed in at least four lakes in Montana so far this month.
Neighboring states are also seeing similar patterns. According to the Wyoming and Idaho DEQ, multiple reservoirs and lakes in each state have also been under health advisories due to HABs this summer.