Fishing closures expand as record heat warms Western rivers

Key Points:

• Record heat and drought in the U.S. West have caused water temperatures in rivers and streams to reach lethal levels for trout, prompting wildlife officials to impose fishing restrictions during certain hours to reduce stress on the fish.
• Montana and Colorado have expanded afternoon fishing bans on multiple rivers, including the Yellowstone River, with closures becoming more routine over the past decade due to rising temperatures linked to climate change.
• Warm water reduces oxygen levels, hindering trout survival and growth, while low reservoir levels fail to sustain river flows; this has led anglers to shift fishing trips to cooler fall months, impacting local economies reliant on trout fishing tourism.
• Studies indicate that "river heat waves" are increasing in snow-dependent mountain regions as climate change alters snowpack patterns, further stressing cold-water fish species like bull trout.
• Fishing-related businesses and educational programs in Montana are adapting to shorter fishing seasons caused by hotter, drier conditions and more frequent wildfires, reflecting long-term environmental changes not observed decades ago.