According to the U.S. Census Bureau, Swain county has a total area of , of which is land and (2.3%) is water. The county is located in the far western part of North Carolina in the Great Smoky Mountains and contains a larger proportion of the Great Smoky Mountains National Park than any other county in North Carolina or Tennessee. The highest point in the county is Clingmans Dome, elevation 6,643 feet, located on the NC/TN border. Clingman's is the third highest peak in North Carolina, and a walkable observation tower is located on its summit. The highest mountain in North Carolina and in the United States east of the Mississippi River is Mt. Mitchell, 6,684 feet, located northeast of Asheville.