The move is to protect the park’s native and wild trout fisheries. High temperatures and low river flow must improve until the fishing ban is lifted.

More geological changes are occurring at Yellowstone National Park, as another hole forms in one of the park's basins. The hole is a blue water spring, discovered by geologists in April as they conducted routine maintenance of temperature logging stations at Norris Geyser Basin, according to the U.S. Geological Survey.

Geologists working in Yellowstone National Park discovered a new pool of strange light blue water this spring. Using satellite imagery, they have now been able to determine exactly how and when this new feature was born.