The dates of fishing season depend entirely on the location. Each jurisdiction has specific rules about fishing requirements. Local fish and wildlife authorities can be consulted to determine the exact dates.
As an example, Yellowstone National Park declares fishing season to be officially open between Memorial Day weekend and the first Sunday of November. During this time period, those with proper permits and licenses can fish the waters of the national park. Other guidelines, like hours and number of fish allowed to be caught, must be adhered to as well. Specific fishing regulations can generally be found wherever permits and licenses are sold.