Yellowstone National Park is closing all rivers and streams for fishing starting Wednesday from 2 p.m. to sunrise because of high water temperatures and low stream flows.Park officials said in a news release that the restriction s are in addition to fishing closures on the Madison, Firehole and Gibbon downstream of Norris campground that have been in effect since July 15.The closures will remain in effect until conditions approve, according to the park.Water temperatures have exceeded 68 degrees Fahrenheit (20 degrees Celsius) in recent days, and flows on many rivers are below long-term averages. These conditions are extremely stressful and can be fatal to fish. The extended forecast calls for continued hot and dry conditions with a slight chance of isolated afternoon thunderstorms, which contribute to continued low stream flows and high-water temperatures.Staff will continue to monitor the water temperatures. The closure may be lifted, or additional restrictions and closures may be put in place depending on condition assessments.The park is advising anglers fish during the coolest times of the day and land fish quickly. Don't play hooked trout to exhaustion, and gently handle fish in the water and let them recover before release. ...read more read less