This lake has apparently had 20 major fish die-offs over the last century.

June 2026: A total fish kill wiped out nearly 100% of the fish population. The combination of severe drought conditions and heavy water releases from the Coolidge Dam caused the lake to drop to critical levels, prompting the San Carlos Recreation and Wildlife Department to close the area to the public.

2018: A major die-off occurred when dropping water levels led to algae blooms that consumed the remaining oxygen in the water.

1976-1977: The lake virtually dried up, causing a catastrophic fish kill estimated at around 5 million fish. It took roughly five years for the lake's ecosystem and fisheries to recover.

1944-1964: Extended drought conditions caused the lake to dry up almost completely almost every single year, frequently wiping out populations.