Alignment: Long Lake to SD-10 south of Long Lake

History and Notes: Designated around 1960, and changed to SD-239 in 1976.

Alignment: Along Minnesota border from Gary south to SD-22.

Distance: 3 miles

History and Notes: Designated in 1976; it had been "SPUR" SD-22 since between 1965 and 1971.

Links: Mr. Yamamoto's SD-101 Page

Alignment: SD-47 west of Hosmer to US-12, 6 miles west of Roscoe

History and Notes: First designated around 1960, applying to the segment from the McPherson County line near Hosmer to US-12. By 1971, an east-west segment from SD-47 to Hosmer was added. Designation changed to SD-253 in 1976.

Alignment: Selby (US-12) to US-12 south of Java

History and Notes: Designated around 1960. In 1976, the Selby to Java segment became SD-130, and the US-12 to Java segment became part of SD-271.

Alignment: West of Hudson to SD-46

History and Notes: Was originally designated as "SPUR" SD-46 around 1970, then changed in 1976. Decommissioned in 1994.

Alignment: North Dakota border north of Artis to Java

History and Notes: Designated around 1965, this route originally existed from SD-10 northward. In 1976, it became part of SD-271.

Alignment: Jefferson to North Sioux City

History and Notes: Designated around 1980, when US-77 was moved onto the I-29 alignment. Decommissioned in 1998. However, SDDOT maintains a small segment of the route extending from I-29 to Jefferson.

Alignment: SD-25 at Claire City to SD-127 at Hammer

Distance: 5 miles

History and Notes: Designated in 1976, replacing a segment of SD-15.

Links: Mr. Yamamoto's SD-106 Page

Alignment: Big Stone City (US-12) northwest to Jct. SD-15

Distance: 12 miles

History and Notes: Runs along Minnesota border. Was designated as SD-15Y until 1976.

Alignment: I-29 west of Dell Rapids to US-18/SD-44 west of Canton

Distance: 40 miles

Intersecting Interstates: I-29 west of Dell Rapids; I-90 and I-229 in Sioux Falls

Multiplexing: Shared alignment with BUSN I-90 and BUSN I-229 through Sioux Falls

Multi-lane segments: Length of route through Sioux Falls

History and Notes: Routing of former US-77 was along this road. Designation of SD-115 may have been based on the original designation of US-77 in this area, which was SD-15. SD-115 was designated around 1980, when US-77 was moved onto I-29.

The segment of SD-115 (then SD-15) between Sioux Falls and US-18 was part of the Custer Battlefield Highway, running from Glacier National Park in Montana to Des Moines, Iowa. Most of the South Dakota segment utilized US-16, except for a small portion south of Sioux Falls.

In 2001, SD-115 was realigned in Sioux Falls. The previous alignment extended from I-90 along Cliff Avenue, then curving southwest on North Drive to Minnesota Avenue, where it continued southward. The new alignment removes the North Drive segment, taking SD-115 west on Benson Road to Minnesota Avenue north of the airport terminal, continuing south.

The POW/MIA Memorial Highway designation was passed by the South Dakota legislature in 2000.

Attractions Along the Way: USS South Dakota Memorial, Washington Pavilion of Arts and Sciences, Old Courthouse Museum, Great Plains Zoo and Delbridge Museum, Center for Western Studies, Falls of the Big Sioux River (all in Sioux Falls); EROS Data Center (east of Baltic)

Alignment: I-90 to New Underwood

History and Notes: A short spur, numbered from US-16, implemented around 1965. This route was decommissioned around 1975, and for awhile in the 1990's, it was unmarked SD-423. It is currently unnumbered.

Alignment: SD-15 at Wilmot to US-12 near Marvin

Distance: 11 miles

History and Notes: Replaced SD-15A in 1976.

Alignment: SD-10 near Sisseton to North Dakota border (ND-127) northeast of Rosholt

Distance: 37 miles

Intersecting Interstates: I-29 near New Effington

History and Notes: This route was designated around 1980, on an old alignment of US-81 east from New Effington, after US-81 was moved onto I-29. By 1984, after US-81 south of New Effington was moved to the interstate, SD-127 was extended to Sisseton.

Links: Mr. Yamamoto's SD-127 Page

Alignment: Selby (US-83) to Java (SD-271)

Distance: 7 miles

History and Notes: Designated in 1976, replacing SD-103.

Alignment: US-12 west of Mina to Brown County border northeast of Mina

Distance: 3 miles

History and Notes: Passes through the Mina Lake Recreational Area.

Alignment: SD-37 on south side of Groton, to US-12 on east side of Groton

Distance: Approximately 1 mile

History and Notes: Indicated in a review of South Dakota state laws regarding each highway. Commissioning date unknown, but decommissioned in February 2004.

Alignment: SD-20 northwest of Watertown to US-212 west of Watertown

Distance: 7 miles

History and Notes: Runs along west side of Lake Kampeska.

Designated in 1976. Was previously SD-23.

Links: Mr. Yamamoto's SD-139 Page

Alignment: Akaska to US-83 east of Akaska

Distance: 3 miles.

History and Notes: In the early 1950's, this route was the start of SD-20. It was changed to Spur SD-20 between 1965 and 1970. SD-144 designation implemented in 1976.

Alignment: SD-47 near the White River to Colome (US-18)

History and Notes: An old designation of the current SD-49. Designation was changed in 1976.

Alignment: SD-50 just west of the SD-314 junction to SD-52 near Lewis and Clark Lake

Distance: 2 miles

Alignment: Jct. SD-15/ SD-20 northwest of Albee east to Minnesota border north of Nassau, MN

Distance: 12 miles

History and Notes: Designated in late 1970's, replacing SD-20A.

Alignment: US-85 near Two Top Butte to Castle Rock (SD-79)

Distance: 5 miles

History and Notes: West end is at geographical center of U.S.

Designated in 1975. Road was previously part of a SD-79 alignment.

Alignment: I-90 at Presho to Nebraska border (US-183) at Wewela

Distance: 76 miles

Intersecting Interstates: I-90 at Presho

Multiplexing: Shared alignment with SD-44 from 3 miles east of Witten to Winner; with US-18 from 10 miles west of Winner to Colome

History and Notes: Highway designated in 1932, but existed further south in 1930. What is currently US-183 in South Dakota had previously been SD-55.

Original routing had US-83 and US-183 positions reversed. The original US-183 started at Vivian, then went west to Murdo. From there, the route went south through Mission to the Nebraska border north of Valentine. By 1944, the route was realigned to extend east from Vivian to Presho, then south through Winner and Colome to the Nebraska border. The Vivian to Presho segment was dropped by 1970.

Follow US-183 across: Nebraska, Kansas, Oklahoma, and Texas

Links: Dale Sanderson's END US-183 Page

Alignment: I-90 in Rapid City to Main St. (SD-79) in Rapid City

Distance: 1.72 miles

Intersecting Interstates: I-90 in Rapid City

Multiplexes: Entire length shared with US-16

NHS: Entire length

History and Notes: Completed by 1962.

Attractions Along the Way: Dinosaur Park (Rapid City); Museum of Geology (Rapid City)

Links: Kurumi's I-190 Page, AARoads I-190 Page