Be sure and join us on the Lower Mountain Fork River in Beavers Bend State Park as Lt. Governor Matt Pinnell and his two sons try fly fishing for the first time. Find out who caught a fish first! The Beavers Bend Fly Shop is the perfect place to get set up for fishing the Lower Mountain Fork River in southeast Oklahoma. They have expert guides who are happy to help you! The Lower Mountain Fork river is one of the most popular and beautiful locations in the state for fly fishing! When it comes to trout fishing, it doesn’t get much better than this!