MCCOOK, Neb. (AP) _ A small hole in an earthen dam north of McCook is being examined to make sure the Red Willow Dam doesn't have structural problems. The U.S. Bureau of Reclamation plans to send engineers to Hugh Butler Lake in southwest Nebraska to determine what caused the hole. Maintenance workers discovered the problem last week. Red Willow Dam is 126 feet tall, and it forms a reservoir that can hold 86,630 acre-feet of water. The bureau's Aaron Thompson has said a plan to fix the dam will be developed after the engineers inspect it. Thompson says the dam is not leaking.