Alignment: North Dakota border (ND-6) north of McLaughlin to US-18 south of Parmlee.

Distance: 260 miles.

Freeway: Belvidere to 7 miles east of Belvidere (co-sign with I-90).

Intersecting Interstates: I-90 at Belvidere and 7 miles east of Belvidere.

Multiplexing: Shared alignment with BIA-4 for 1 mile, south of Little Eagle; with SD-20 from 5 miles west of Trail City to 5 miles northeast of Timber Lake; with US-212 from 4 miles east of Eagle Butte to 2 miles west of Eagle Butte; with US-14 from SD-34 to Midland; with I-90 for 7 miles east from Belvidere.

Unpaved Segments: 5 miles south of Belvidere to SD-44.

History and Notes: Southern portion of SD-63 (1926) originally ran from Kadoka to Nebraska border along current SD-73. Alignment was changed by 1936, when SD-63 was pulled back to US-14, and SD-73 applied across the southern segment.

Route extensions were made in the 1960's. Around 1960, SD-63 was extended south to US-16 near Stamford. By 1965, it was multiplexed with SD-40 south from Belvidere, ending west of Cedar Butte. By 1971, it was extended to US-18 near Parmlee, where it remains today.

On the north end, SD-63 originally did not exist between US-12 and SD-8 (current SD-20), and the north end was at Timber Lake. Between 1948 and 1953, the road was realigned to start about 3 miles east of Firesteel. Between 1965 and 1971, the far northern segment was extended south from McLaughlin to SD-20, then west to meet up with the other segment.

Alignment: North Dakota border (ND-31) near McIntosh to US-212 east of Dupree.

Distance: 68 miles.

Multiplexing: Shared alignment with US-12 for a short distance east of McIntosh; with SD-20 for 4 miles west from Isabel.

History and Notes: 1926 alignment extended south along current SD-63 to US-16, then east to Murdo, and south to the Nebraska border along current US-83. By 1932, the southern end was truncated to US-212 at Dupree, where it remains today.

Alignment: Hot Springs (BYPASS US-18) to Nebraska border (NE-2/NE-71) near Ardmore.

Distance: 30 miles

Unpaved Segments: Angostura Reservoir to near Rumford. This is expected to be paved by 2004.

History and Notes: SD-71 is part of a multi-state Highway 71, beginning in Hot Springs, SD, and ending southwest of LaJunta, CO. Previously, it was part of SD-87. Renumbering took place between 1957 and 1962.

Attractions Along the Way: Mammoth Site (Hot Springs).

Links: Mr. Yamamoto's SD-71 Page

Alignment: North Dakota border (ND-49) at Thunder Hawk to Nebraska border (NE-61) south of Martin.

Distance: 250 miles

Freeway: Kadoka to 8 miles west of Kadoka (co-sign with I-90).

Intersecting Interstates: I-90 at Kadoka and 8 miles west of Kadoka.

Multiplexing: Shared alignment with US-12 from Lemmon to 1 mile east of Thunder Hawk; with SD-20 from 2 miles east of Meadow to 3 miles west of Coal Springs; with US-212 for 5 miles west from Faith; with SD-34 from Howes to Billsburg; with I-90 from Exit 143 to Kadoka; with US-18 from 7 miles south of Patricia to Martin.

History and Notes: 1926 alignment only included the Thunder Hawk to Faith segment. By 1932, the road was moved west several miles, extending south from Lemmon to meet up with SD-18 before continuing on to Faith. By 1936, the route was extended south onto what had been SD-24 to near Plainview, then southeast along a newly designated route to Philip. The route then went to Kadoka, and replaced a segment of SD-63 south to the Nebraska line.

Greg Wysk of St Cloud, MN shares some information on SD-73:

Highway 73 used to actually end at a junction with U.S. 12 at Lemmon, about 1/2 mile south of the Dakota border. It got multiplexed with U.S. 12 through Lemmon to Thunder Hawk and connected with N.D. 49 in 1978 or so. What happened is that S.D. decided to build a railroad overpass and a short extention to connect with the finished Highway 49. Prior to that 49 ended at the border, and you had to take a gravel township road about 1 1/2 miles through Thunder Hawk to U.S. 12. What's interesting is that S.D. was originally going to call this 1/2 mile or so road another number -- Highway 69 I think (unfortunately, I don't have access to the old newspapers). But they just multiplexed 73 along 12.

Attractions Along the Way: Petrified Wood Park (Lemmon); Hugh Glass Monument (southwest of Shadehill); Badlands Petrified Gardens (Kadoka).

Alignment: Segment 1: North Dakota border near Hettinger, ND, to Reva
Segment 2: US-18 to Nebraska border southeast of Denby.

History and Notes: The northern segment was designated between 1948 and 1953, but was renumbered as a part of SD-79 around 1975; the SD-75 designation was then moved approximately 18 miles eastward. The southern segment was in place by 1936 (although twice as long, due to a different US-18 alignment). This segment was renumbered SD-391 in 1976.

Alignment: Northwest Perkins County from North Dakota border (ND-8) to SD-20 east of Prairie City.

Distance: 28 miles.

History and Notes: The SD-75 alignment was moved from far eastern Harding County to this alignment in 1976.

Alignment: Minnesota border at Big Stone City to Iowa border at North Sioux City

History and Notes: This U.S. route was extended north of its previous terminus in Sioux City, IA, in 1930, to Ortonville, MN. Followed path of current US-12, SD-15, I-29, SD-115, and SD-105.

Gradually, beginning in the 1960's, US-77 was realigned onto segments of I-29:

• 1963: SD-50 to Jefferson
• By 1965: Multiplex extended north to US-18
• By 1971: Separate multiplex from 3 miles west of Dell Rapids to Brookings
• By 1977: Northern multiplex extended from Brookings to west of Toronto
• By 1981: Segments between Dell Rapids and US-18 (old alignment turned into SD-115), and Jefferson to North Sioux City (old alignment turned into SD-105).

The entire route was decommissioned in South Dakota in 1982, when the northern terminus was pulled back to Sioux City.

Follow US-77 across: Iowa, Nebraska, Kansas, Oklahoma, and Texas
Historical routings across: Minnesota

Alignment: North Dakota border (ND-22) northeast of Ralph to US-18/US-385 east of Hot Springs.

Distance: 244 miles.

Freeway: Black Hawk to Sturgis (co-sign with I-90).

NHS: Newell to Hot Springs.

Multi-Lane Segments: Southeast edge of Rapid City to Hermosa, as part of the Heartland Expressway.

Intersecting Interstates: I-90 at Sturgis and Black Hawk.

Multiplexing: Shared alignment with SD-20 for 6 miles east from Reva; with US-212 for 3 miles south from Newell; with SD-34 for 5 miles east from Sturgis; with I-90 and US-14 from Sturgis to Black Hawk; with SD-44 through Rapid City; with Truck BYPASS US-16 on the southeast side of Rapid City; with SD-40 for less than 1 mile near Hermosa.

History and Notes: 1926 alignment had SD-79 following US-85 north of Sturgis. By 1932, it was several miles further east, as US-85 extended through Spearfish and Belle Fourche. In addition, the route continued south along US-16 (current US-14) to Rapid City, then to the Nebraska border south of Oelrichs. Also, the segment from Rapid City to Hermosa was part of the short-lived US-216 in 1934.

In 1936, the northern alignment started at US-85 near the Harding/Butte County line, heading east to the old town of Mason, then south to meet with existing SD-79 north of Castle Rock. The ending point changed by 1971, when US-85 was rerouted northeast to near Castle Rock Buttes, and SD-79 was pulled back to intersect. In 1976, the diagonal segment from Castle Rock became SD-168, and SD-79 was extened northeast to Reva, before heading north to the North Dakota border on what had been SD-75.

The segment between Hermosa and the Nebraska line were straightened out in the 1950's. By around 1960, the south end of SD-79 was pulled back to 5 miles east of Hot Springs, with the new US-385 absorbing the old route to Nebraska.

Segment from Hot Springs to Rapid City is part of the future "Heartland Expressway", which will link Denver and Rapid City. The expressway will connect with I-90 at Elk Creek Road (exit 61). The segment from Hot Springs to Hermosa is scheduled to be completed by 2005.

Attractions Along the Way: Bear Butte State Park (northeast of Sturgis); Sturgis Motorcycle Rally (Sturgis); National Motorcycle Hall of Fame (Sturgis); Poker Alice House (Sturgis); Old Fort Meade (Sturgis); Petrified Forest of the Black Hills (east of Piedmont); Chapel in the Hills (Rapid City); Dinosaur Park (Rapid City); Museum of Geology (Rapid City); The Journey Museum (Rapid City); Mammoth Site (Hot Springs)

Links: AARoads' Heartland Expressway Page

Alignment: North Dakota border (I-29/US-81) near Victor to Nebraska border (US-81) at Yankton.

Distance: 239 miles.

Freeway: Watertown to North Dakota border (co-sign with I-29).

NHS: Entire route.

Intersecting Interstates: I-29 at Watertown; I-90 at Salem.

Multi-lane Segments: SD-50 to north edge of Yankton.

Multiplexing: Shared alignment with I-29 from the North Dakota border to the north side of Watertown; with SD-22 for 2 miles west of Castlewood; with SD-28 for 1 mile noth from Alsville; with US-14 for 3 miles south from Arlington; with SD-34 from Madison to 2 miles northwest of Winfred; with SD-50 through Yankton.

Lewis and Clark Trail: Yankton (multiplexed segment with SD-50).

History and Notes: US-81 was an original 1926 highway. It was initially co-signed as SD-21. Part of the "Meridian Highway" in the U.S., and the multi-national Pan American Highway, which runs from Winnipeg, Canada, to Panama.

Little change in the route was noted over the years, except for a realignment of the segment between SD-10 and US-12 around 1950, when the road was moved about 5 miles east. Then, as I-29 was being completed, US-81 was moved onto the interstate. This occurred between Watertown and Peever, and from New Effington to the North Dakota border around 1980. This particular move resulted in the segment from New Effington to North Dakota via Rosholt to be renumbered as SD-127. By 1984, all of US-81 north of Watertown was on the interstate, and the old alignment from New Effington to Sisseton had also become part of SD-127.

On the south end, replacement of the US-81 bridge over the Missouri River is being planned. The original bridge was built in 1924, the last link in the Meridian Highway. It is a double-deck bridge, designed for trains on the lower deck and vehicles on the upper deck. The trains were never brought across the bridge, so it was switched to use southbound traffic on the lower deck, and northbound traffic on the upper deck. A new bridge and alignment, a few blocks west, is in the planning process. The future of the old bridge, which is on the National Register of Historic Places, is unknown.

Attractions Along the Way: Redlin Art Center (Watertown); Arthur Mellette House (Watertown); Prairie Village (Madison); Lake Herman State Park (west of Madison); Lewis and Clark Visitors Center and Gavins Point Dam (Yankton); Dakota Territorial Capitol (Yankton); Cramer-Kenyon Heritage Home (Yankton).

Follow US-81 across: North Dakota, Nebraska, Kansas, Oklahoma, and Texas

Alignment: North Dakota border (US-83) north of Herreid to Nebraska border (US-83) north of Valentine, NE.

Distance: 242 miles.

Freeway: Murdo to Vivian (co-sign with I-90).

NHS: Entire route.

Multi-lane Segments: US-12 junctions north and south of Selby; Pierre to Jct. BYPASS US-83. An upgrade to 4-lane status is also planned for the Pierre to I-90 segment.

Spurs and Alternates: BYPASS US-83 east of Pierre, from the SD-34 junction north to US-83/US-14.

Multiplexing: Shared alignment with SD-10 from 2 miles south of the North Dakota border to 3 miles north of Mound City; with US-12 from 5 miles northwest of Selby to 4 miles south of Selby; with SD-20 from 5 miles northwest of Selby to the Walworth/Potter County line; with US-212 for 1 mile, west of Gettysburg; with US-14 from 5 miles west of Blunt to Ft. Pierre; with SD-34 through the west part of Pierre; with I-90 from Vivian to Murdo; with SD-44 for 3 miles south from White River; with US-18 for 3 miles west from Mission

Lewis and Clark Trail: North jct. US-12 to US-212; Pierre.

History and Notes: Segment from Pierre northward was assigned in 1927, following the old SD-53 routing. Improvements over the years in this segment include a diagonal route to west of Blunt, completed in the mid 1930's, and relocation of the US-212 to SD-144 segment (6 miles west of previous alignment) to straighten the route, completed between 1944 and 1948.

The segment between Pierre and the Nebraska line was designated by 1932. However, the routing was basically reversed with what is now US-183. The US-83 extension went from Pierre to Vivian, then east to Presho. From there, it extended south, then east to Winner. US-83 entered Nebraska south of Colome. By 1944, the alignment changed to head west from Vivian, then south from Murdo.

The Pearl Harbor Memorial Highway designation (US-83 segment from I-90 to Ft. Pierre) was passed by the South Dakota legislature in 2000.

Construction began in August 2002 on upgrading US-83 to an expressway between Fort Pierre and I-90. The southernmost 9 miles are expected to be completed by July 2003, with the overall project completed in 2005.

Attractions Along the Way: Bangor Monument (south of Selby); State Capitol (Pierre); South Dakota State Museum (Pierre); Oahe Dam (north of Pierre); South Dakota National Guard Museum (Pierre); South Dakota Discovery Center and Aquarium (Pierre); World War II Memorial (under construction in Pierre); Fort Pierre (Ft. Pierre); Verendrye Monument (Ft. Pierre).

Follow US-83 across: North Dakota, Nebraska, Kansas, Oklahoma, and Texas

Alignment: Deadwood to Hot Springs.

History and Notes: Previously known as the "Potash Highway", this 1926 road was the original designation of the current US-385. Was changed to US-85E around 1931, then to ALT US-85 by 1938. The US-385 number was assigned in the late 1950's.

Alignment: North Dakota border (US-85) north of Ludlow to Wyoming border (US-85) southwest of Lead.

Distance: 156 miles.

Freeway: Spearfish to near Elkhorn Peak (co-sign with I-90).

NHS: Entire route.

Intersecting Interstates: I-90 at Spearfish and north of Deadwood.

Multiplexing: Shared alignment with SD-20 for 2 miles south from Buffalo; with I-90 and US-14 from Spearfish to west of Elkhorn Peak; with ALT US-14 from northeast of Deadwood to Cheyenne Crossing

Multi-lane Segments: 2 mile stretch south from I-90, to the north of Deadwood. The segment from I-90 to Belle Fourche is expected to become 4 lanes by 2004.

History and Notes: Original 1926 highway, known as the "Canam Highway". The segments in Harding and Butte Counties were straightened in the 1950's.

Attractions Along the Way: Geographical Center of the U.S. (northeast of Belle Fourche, at Jct. SD-168); High Plains Heritage Center (Spearfish); Black Hills Passion Play (Spearfish); Preacher Smith Monument (north of Deadwood); Calamity Jane and Wild Bill Hickok Graves (Deadwood); Broken Boot Gold Mine (Deadwood); Homestake Gold Mine (Lead).

Follow US-85 across: North Dakota, Wyoming, Colorado, New Mexico, and Texas

Alignment: US-85 at Pluma to Nebraska border south of Oelrichs.

History and Notes: An early designation of US-385, used in the early and mid 1930's.

Alignment: Deadwood to Wyoming border west of Edgemont.

History and Notes: This route followed what is now US-385 from Deadwood to Hot Springs, and was co-signed with US-18 from Hot Springs westward. The designation was created between 1932 and 1936. It was replaced by 1960 with the US-385 designation.

Alignment: US-16/ US-385 at St. Elmo Peak to US-385 near Wind Cave.

Distance: 40 miles.

History and Notes: Designated around 1936, extending to the Nebraska border at Ardmore. The Hot Springs to Nebraska segment was renumbered as SD-71 by 1965, and the south end of SD-87 was pulled back to US-385 at Wind Cave National Park.

Closed during the winter.

Attractions Along the Way: Harney Peak, highest point in South Dakota (south of Hill City); Custer State Park (east of Custer); Wind Cave National Park (north of Hot Springs)

Links: Mr. Yamamoto's SD-87 Page

Alignment: US-18 west of Hot Springs to SD-87 near Sylvan Lake.

Distance: 40 miles.

Multiplexing: Shared alignment with ALT US-16 through Custer; with US-385 from Custer to Pringle.

History and Notes: Original (circa 1950) alignment was from Spearfish to west of Hot Springs near Parker Peak. The northern segments were later replaced by ALT US-14 and Forest Service roads. The Custer to Sylvan Lake segment was once (pre-1957) part of an old ALT US-85 alignment.

Attractions Along the Way: Cathedral Spires (north of Custer); The Needles (north of Custer); Custer County 1881 Courthouse (Custer); Flintstones Bedrock City (Custer); National Museum of Woodcarving (southwest of Custer).

Links: Mr. Yamamoto's SD-89 Page

Alignment: Wyoming border (I-90/ US-14) northwest of Spearfish to Minnesota border (I-90) east of Sioux Falls.

Distance: 412 miles

Intersecting Interstates: I-190 in Rapid City; I-29 and I-229, both in Sioux Falls.

NHS: Entire length.

Multiplexing: Shared alignment with US-14 from the Wyoming border to 1 mile east of Wall; with US-85 from Spearfish to near Elkhorn Peak; with SD-34 from Whitewood to Sturgis; with SD-79 from Sturgis to Black Hawk; with SD-73 from Exit 143 to Kadoka; with SD-63 from Belvidere to Exit 170; with US-83 from Murdo to near Vivian; with SD-50 from southeast of Chamberlain to south of Pukwana; with SD-45 from Kimball to Exit 289.

Business Routes: Loop I-90 in Sturgis, Rapid City, Wall, Murdo, Vivian, Chamberlain, Kimball, Plankinton, Mitchell; Spur I-90 in Sioux Falls.

Lewis and Clark Trail: Chamberlain to Pukwana.

History and Notes: Construction status of I-90:

• Segments through Rapid City and from Wall to near Interior were under construction in 1960.
• 1962: Segments open from Piedmont to Ellsworth AFB, New Underwood to northwest of Wasta; bypass of the Badlands; and US-77 to Minnesota border. Under construction from Ellsworth AFB to New Underwood; and Hartford to US-77.
• 1971: Open from near Whitewood to Vivian, and Chamberlain to Minnesota border.
• 1975: Only segment left to build was from the Wyoming border to Spearfish. Entire route completed by 1978.

Attractions Along the Way: High Plains Heritage Center (Spearfish); Black Hills Passion Play (Sturgis); Sturgis Motorcycle Rally (Sturgis); National Motorcycle Museum & Hall of Fame (Sturgis); Reptile Gardens (Rapid City); Dinosaur Park (Rapid City); Museum of Geology (Rapid City); Black Hills Caverns (Rapid City); Air and Space Museum (Ellsworth Air Force Base); Wall Drug (Wall); Badlands National Park (Wall); National Grasslands Visitors Center (Wall); Badlands Petrified Gardens (Kadoka); 1880 Town (east of Belvidere); Pioneer Auto Museum (Murdo); Akta Lakota Museum (Chamberlain); South Dakota Hall of Fame (Chamberlain); South Dakota Tractor Museum (Kimball); Corn Palace (Mitchell); Enchanted World Doll Museum (Mitchell); USS South Dakota Memorial (Sioux Falls); Old Courthouse Museum (Sioux Falls); Center for Western Studies (Sioux Falls); Great Plains Zoo and Delbridge Museum (Sioux Falls); Sioux Empire Medical Museum (Sioux Falls); EROS Data Center (northeast of Sioux Falls).

Follow I-90 across: Washington, Idaho, Montana, Wyoming, Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, New York, and Massachusetts

Links: Exit Listings at Highway Heaven, Rapid City I-90 Reconstruction