U.S. Route 16A

U.S. Route 16A
Route information
Auxiliary route of US 16
Defined by SDCL §31-4-139
Maintained by SDDOT
Length:	36.971 mi (59.499 km)
Major junctions
West end:	US 16 / US 385 / SD 89 in Custer
East end:	US 16 near Keystone
Location
Counties:	Custer, Pennington
Highway system
United States Numbered Highways List Bannered Divided Replaced South Dakota Highways ← US 16 SD 17 →

U.S. Route 16A (US 16A) is a scenic United States highway, which divides from U.S. Route 16 in the Black Hills of South Dakota. The highway's western terminus is a junction with US 16 and US 385 in Custer, South Dakota. The eastern terminus is at an interchange with US 16 called the Keystone Wye south of Rapid City, South Dakota.

Route description

Mount Rushmore seen from a tunnel on US 16A

The route passes through Keystone, South Dakota; Norbeck Wildlife Refuge; Mount Rushmore National Memorial; and Custer State Park (including State Game Lodge and Legion Lake); before rejoining the parent highway.

Pigtail bridge at the exit of the same tunnel

US 16A is famous for its scenic, one-lane tunnels aligned to frame the faces on Mount Rushmore, its "pigtail bridges", and its sections of divided highway but with single (and narrow) lanes on each roadway. It is the only route which can be used to drive through Custer State Park without having to pay an entrance fee for the park, provided the traveler does not stop in the Park.

Portions of US 16A are known as the Iron Mountain Road. The route includes most of the tunnels on the South Dakota state highway system, including the only four-lane tunnel in the state, just north of Keystone. Part of the highway is also a boundary of the Black Elk Wilderness. The Iron Mountain portion of the road is not maintained in the winter. The road, like several other scenic roads in the Black Hills, was originally laid out by Governor Peter Norbeck, specifically to create a very scenic, slow-speed road for tourists. The section of US 16A from SD 89 to SD 244 is known as the Peter Norbeck Memorial Byway in honor of the governor. At the highest point of the byway, on the summit of Iron Mountain, there is a small memorial to Governor Norbeck.

History

An older road through the Badlands of South Dakota (now South Dakota Highway 240) was designated US 16A between 1944 and 1980.

Major intersections

County	Location	mi	km	Destinations	Notes
Custer	Custer	0.000	0.000	US 16 east / US 385 north US 16 west / US 385 south / SD 89 south	West end of SD 89 concurrency
		0.804	1.294	SD 89 north	East end of SD 89 concurrency
	Custer State Park	6.447	10.375	SD 87 south	West end of SD 87 concurrency
		7.875	12.674	SD 87 north	East end of SD 87 concurrency
		16.226	26.113	SD 36 east
Pennington	Mount Rushmore	33.221	53.464	SD 244 west
	Keystone	34.321	55.234	SD 40 east
	Keystone Wye	36.971	59.499	US 16
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus

External links

• The South Dakota Highways Page: Highways 1 to 30