Green River, 370 mi/595 km long, in Ky. and Ind.; rises in central Lincoln co., Ky., flows SW past Liberty, then W through Green River L. reservoir, past Greensbury and Munfordville in central Ky., through Mammoth Cave Natl. Park, then NW past Morgantown and Calhoun to the Ohio R., 5 mi/8 km S of Evansville, Ind.