High Quality Content by WIKIPEDIA articles! The Upstate is the region in northwestern South Carolina, United States, also known as The Upcountry, which is the historical term. Although loosely defined among locals, the general definition includes the 10 counties of the commerce-rich I-85 corridor in the northwest corner of South Carolina. The region's population was 1,220,542 at the 2000 Census. A July 1, 2008 United States Census Bureau estimate placed the population at 1,335,571. The Upstate is the fastest growing region in the state, and given its strategic position between Atlanta and Charlotte, future development and growth prospects are bright.