U.S. Federal Route 71 is the main north-south highway in Central Audubon County. This connects Hamlin to Interstate 80. U.S. Rt. 71 passes through the following towns in Audubon County. Brayton Exira Hamlin Audubon U.S. Rt. 71 is not multi-plexed in Audubon County. U.S. Rt. 71 intersects the following highway in Audubon County. Iowa State Route 44, at Hamlin.