Site Navigation Iowa Minnesota Montana Nebraska North Dakota South Dakota Wyoming     Interstate 90 South Dakota Overview Interstate 90 is the longest Interstate highway in South Dakota, with just about 412 miles through the state. The highway parallels U.S. 14 from the Wyoming State Line east to Wall via Rapid City; it replaced U.S. 16 from Rapid City east to the Minnesota State Line. Beginning in Seattle, Washington, at the intersection with Washington 519 just west of Interstate 5 in Seattle, Washington, Interstate 90 crosses the country along the northern tier. After passing through Chicago, Interstate 90 follows a series of toll roads and turnpikes east to Logan International Airport in Boston, Massachusetts. For more detail on nationwide Interstate 90, go to the Interstate 90 Guide. Interstate 90 Business Loops There are 14 business loops and spurs from Interstate 90 in South Dakota: Spearfish Sturgis Rapid City Wall Kadoka Belvidere (spur) Murdo Vivian Presho Oacoma/Chamberlain White Lake (spur/unsigned) Plankinton Mitchell Sioux Falls (spur) Interstate 90 South Dakota Guides Interstate 90 East (Sioux Falls vicinity) Interstate 90 West (Rapid City to Wyoming) Business Spur Interstate 90 & South Dakota 115 Business (Downtown) Spur Interstate 90 follows South Dakota 115 (former U.S. 77) south from Interstate 90 into downtown Sioux Falls. Pictured here is the first reassurance assembly on Cliff Avenue near the Exit 399 diamond interchange with Interstate 90. Photo taken 04/20/07. Interstate 90 west continues three miles to junction Interstate 29 on the northwest side of Sioux Falls. Photo taken 04/20/07. Cliff Avenue north at junction Interstate 90 in north Sioux Falls. Business (Downtown) Spur Interstate 90 & South Dakota 115 share pavement along Cliff Avenue between Benson Road and Exit 399 of Interstate 90. The business spur ends here as South Dakota 115 continues along former U.S. 77 north toward Baltic. Photo taken 04/20/07. Other Scenes Pertaining to Interstate 90 This view of Interstate 90 is afforded on the transition ramp from northbound Interstate 190 in Rapid City during the late afternoon. Photo taken 09/03/04. Page Updated March 26, 2008.