U.S. Route 321

U.S. Route 321
US 321 highlighted in red
Route information
Auxiliary route of US 21
Length	516.9 mi[1][2][3] (831.9 km)
Existed	1931–present
Tourist routes	Western York Scenic Byway
Major junctions
South end	US 17 in Hardeeville, SC
Major intersections	I-26 in Cayce, SC I-20 in Columbia, SC I-85 in Gastonia, NC I-40 in Hickory, NC I-26 / US 19W / US 23 in Johnson City, TN I-40 in Newport, TN I-75 in Lenoir City, TN
North end	I-40 / SR 73 / SR 95 near Lenoir City, TN
Location
Country	United States
States	South Carolina, North Carolina, Tennessee
Counties	SC: Jasper, Hampton, Allendale, Bamberg, Orangeburg, Lexington, Richland, Fairfield, Chester, York NC: Gaston, Lincoln, Catawba, Burke, Caldwell, Watauga, Avery TN: Johnson, Carter, Washington, Greene, Cocke, Sevier, Blount, Loudon
Highway system
United States Numbered Highway System List Special Divided
← SC 319 SC → SC 322 ← US 311 NC → NC 343 ← SR 320 TN → SR 321

U.S. Route 321 (US 321) is a spur of U.S. Route 21. It runs for 516.9 miles (831.9 km) from Hardeeville, South Carolina to Lenoir City, Tennessee; with both serving as southern termini. It reaches its northernmost point at Elizabethton, Tennessee, just northeast of Johnson City. Because of its unusual "north–south–north" routing, U.S. Route 321 intersects both Interstate 40 and U.S. Route 70 three separate times. The highway serves different roles in each state: An alternate route to interstates in South Carolina, a major highway in North Carolina, and a scenic route in Tennessee.