U.S. Route 16 in South Dakota

U.S. Highway 16 (US 16) is a 69-mile-long (111 km) east–west U.S. Highway in the western part of the U.S. state of South Dakota. It travels between Yellowstone National Park in Wyoming and Rapid City. In South Dakota, the highway extends from the Wyoming state line near Newcastle, Wyoming to Interstate 90 (I-90) in Rapid City.

U.S. Highway 16 marker

U.S. Highway 16
Current US 16 highlighted in red
Route information
Maintained by SDDOT
Length69.00 mi[1] (111.04 km)
Major junctions
West end US 16 at Wyoming state line
East end I-190 / I-90 in Rapid City
CountiesCuster, Pennington
Highway system
  • South Dakota Highways
SD 15SD 16

Route descriptionEdit

US 16 is also known as Mount Rushmore Road in western South Dakota. The highway enters South Dakota east of Newcastle, Wyoming. It travels near Jewel Cave, the third-longest cave in the world.[2] The highway goes through the city of Custer and shares alignment with US 385. East of Hill City, US 16 splits off US 385. It then becomes a four-lane divided highway, with the two roadways separated by up to 0.5 miles (0.80 km) in some places, including the old gold-mining town of Rockerville, South Dakota, which is contained entirely in the median of US 16. In Rapid City, US 16 follows Mount Rushmore Road to a concurrency with SD 44 (Omaha Street) to the southern terminus of I-190. US 16 stays concurrent with I-190 until both highways end at I-90.

This section of US 16 is defined at South Dakota Codified Laws § 31-4-138.[3]


US 16 formerly ran all the way across the state, to the Minnesota state line east of Sioux Falls. It entered the state on the current routing of US 14/I-90 (the current routing is former US 216), and followed the US 14 routing to Rapid City. It joined U.S. Route 216 in Rapid City, and continued east into Box Elder. "Highway 14-16," as it was known, was a divided highway through most of Box Elder before returning to a two-lane road. (This road is still in use today, and still referred to as "14-16.") US 16 traveled east to New Underwood, then continued through the foothills to Wasta. The highway ran north of Wasta, across the Cheyenne River, then ran southeast to Wall. In Wall, an alternate route of US 16 (present day SD 240) split from the highway and headed south, through the Badlands National Monument (now Badlands National Park). US 14 and US 16 split south of Philip, with US 14 travelling due east and US 16 continuing south (following present-day SD 73 to its intersection with the eastern end of US 16 Alternate. From there, US 16 travels due east, on the present-day routing of South Dakota Highway 248. The highway followed this routing through Kadoka, Murdo, and Vivian, where it intersected U.S. Route 83. The highway continued east to Reliance, where present-day SD 248 ends. US 16 then returned to the current routing of I-90, and followed this routing to Oacoma, where it followed the current I-90 Business Loop to a bridge over the Missouri River into Chamberlain. East of Chamberlain, US 16 followed present day Old Airport Road to East King Street, then turned onto 249th Street just north of where I-90 now lies. It followed 249th Street to Pukwana, present-day 350th Avenue to an intersection with SD 47 (now SD 50), 251st Street to Kimball, and 252nd Street to White Lake. US 16 then followed present-day County Road 34 (also named Old Highway 16) to Mount Vernon and present-day 254th Street to Mitchell. It then followed what is now SD 38 east to 421st Avenue, 421st Avenue to Alexandria, SD 262 to Bridgewater, and SD 42 to Sioux Falls.The highway followed Minnesota Avenue (SD 115), 6th Street, Sycaomre Avenue, Madison Street, and Splitrock Boulevard (SD 11) to Brandon. It then followed present-day Aspen Boulevard from Brandon east to the Minnesota state line north of Valley Springs.


Visible abandoned sectionsEdit

Visible stub locations are listed from west to east.

Three stubs near Wasta:
  • SD 248 and SD 47 meet south of Reliance. SD 248 travels west and south, while SD 47 travels north and east. US 16 travelled straight through this intersection, west to east, and followed present-day SD 47 east. When SD 47 turns to cross the Interstate, a stub of US 16 extends east from this turn for about 3 miles before crossing the highway itself on 245th Street. The pavement shifting this alignment back to the I-90 alignment is no longer present, but a dirt track shows the former routing. (43°50′48″N 99°30′29″W / 43.846682°N 99.508129°W / 43.846682; -99.508129)

Major intersectionsEdit

Custer0.000.00  US 16 west – NewcastleContinuation into Wyoming
Custer26.4642.58   US 385 south / SD 89 south – Wind Cave National Park, Hot SpringsWestern end of US 385 and SD 89 concurrencies
26.9643.39   US 16A east / SD 89 north – Custer State ParkEastern end of SD 89 concurrency
Pennington37.4960.33  SD 87 south (Needles Highway) – Sylvan Lake, Custer
37.6960.66  SD 244 east – Mount Rushmore
Hill City40.5165.19    
   US 16 Truck east / US 385 Truck north
   US 16 Truck west / US 385 Truck south
45.0072.42  US 385 north – Deadwood, LeadEastern end of US 385 concurrency, also known as Three Forks
50.6081.43  US 16A west – Keystone, Mount RushmoreDirectional-T interchange, also known as the Keystone Wye
RockervilleInterchange; left exits and entrances
Rapid City64.19103.30  
   US 16 Truck to I-90
  I-90 Bus. east (St. Joseph Street)One way eastbound only
  I-90 Bus. west (Main Street)One way westbound only
  SD 44 east (Omaha Street)Western end of SD 44 concurrency
   I-190 north / SD 44 east (Omaha Street)Eastern end of SD 44 concurrency; western end of I-190 concurrency; southern terminus of I-190
69.00111.04   I-90 / I-190 endsEastern terminus; eastern end of I-190 concurrency; northern terminus of I-190; trumpet interchange
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

Special routesEdit

Special routes of US 16 in South Dakota consist of an alternate route that runs from Custer to near Keystone as well as truck routes in Hill City and Rapid City, and formerly included a business route in Rapid City and an alternate route between Wall and Kadoka.


  1. ^ a b "State Highway Log: Rapid City Region" (PDF). South Dakota Department of Transportation. January 2017. pp. 23–24. Retrieved April 8, 2017.
  2. ^ "Jewel Cave National Monument". U.S. National Park Service. Retrieved May 18, 2008.
  3. ^ South Dakota Codified Laws

External linksEdit

Route map:

KML is not from Wikidata