Alignment: Rosebud to US-18 west of US-83

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system; runs through the Rosebud Indian Reservation.

Alignment:
Segment 1: Custer County border southwest of Red Shirt to SD-44 east of Potato Creek
Segment 2: SD-50 southeast of Ft. Thompson to SD-45 south of Gann Valley
Segment 3: SD-63 northeast of Green Grass to jct. BIA-3/BIA-4 east of White Horse

Multiplexing: (Segment 1) Shared alignment with BIA-41 for 1.5 miles in northwest Shannon County; with BIA-27 from Rockyford to Sharps Corner

Unpaved Segments: (Segment 1) BIA-41 to BIA-27

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system. Segment 1 runs through the Pine Ridge Indian Reservation Segment 2 through the Crow Creek Indian Reservation; and Segment 3 through the Cheyenne River Indian Reservation.

Alignment:
Segment 1: Lake Sharpe north of Lower Brule to SD-47 north of Reliance
Segment 2: US-212 near Ridgeview to BIA-4 near White Horse

Multiplexing: Shared alignment with BIA-10 for 2 miles southeast from Lower Brule (Segment 1)

Lewis and Clark Trail: Lower Brule to SD-47 (Segment 1)

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system. Segment 1 runs through the Lower Brule Indian Reservation; Segment 2 runs through the Cheyenne River Indian Reservation.

Alignment: Segment 1: Unmarked county road 12 miles north of Timber Lake to US-12 near the west branch of Lake Oahe
Segment 2: SD-20 east of Trail City to White Horse
Segment 3: Ft. Thompson (SD-47) to SD-50 southeast of Ft. Thompson

Multiplexing: (Segment 1) Shared alignment with SD-63 for 1 mile south of Little Eagle.

Unpaved Segments: (Segment 1) Entire route, except for the first 5 miles and the multiplex with SD-63.

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system. Segment 1 runs through the Standing Rock Indian Reservation; Segment 2 runs through the Cheyenne River Indian Reservation; and Segment 3 runs through the Crow Creek Indian Reservation.

Alignment: BIA-6 near Cherry Creek to BIA-15 south of Dupree

Unpaved Segments: Entire route

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system; runs through the Cheyenne River Indian Reservation.

Unpaved Segments: Entire route

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system; runs through the Cheyenne River Indian Reservation.

Alignment:
Segment 1: 403rd Ave. in Todd County (southeast of Parmelee) to Rosebud
Segment 2: US-212 west of Marksville to BIA-4 north of Promise

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system. Alignment 1 runs through the Rosebud Indian Reservation; Alignment 2 runs through the Cheyenne River Indian Reservation.

Alignment: Montana border near Camp Crook to Mobridge

History and Notes: This route was originally designated in the mid 1920's as SD-18. Around 1935, the number was changed to SD-8 designation, then to an extension of SD-20 between 1965 and 1970.

Alignment:
Segment 1: SD-34/SD-73 east of Howes to SD-63 near the Cheyenne River crossing
Segment 2: SD-63 in northeast Ziebach county to BIA-4 southeast of Trail City

Unpaved Segments: Entire route.

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system; runs through the Cheyenne River Indian Reservation.

Alignment: SD-63 southwest of Eagle Butte to jct. BIA-8/BIA-19 southeast of Parade.

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system; runs through the Cheyenne River Indian Reservation.

Alignment: Britton to North Dakota border.

History and Notes: This route was originally a segment of SD-25. Around 1935, SD-25 was adjusted to extend 6 miles east from Britton, before heading north; the original route north from Britton was designated as SD-9. Around 1950, the route number was dropped. This road is currently an unnumbered county road.

Alignment: Pollock (SD-1804) to Minnesota border (MN-27) near Browns Valley, MN

Distance: 193 miles

Intersecting Interstates: I-29 east of Sisseton

Multiplexing: Shared alignment with SD-47 through Eureka; with SD-45 from the SD-247 junction to Leola; with US-281 for 3 miles near Barnard; with SD-37 for 2 miles northeast of Houghton; with SD-27 for 6 miles eastward from Britton

History and Notes: Formerly the "Glacier Trail", SD-10 started out in 1926 as SD-12. Number changed in 1927, presumably to avoid confusion with nearby US-12.

Segment west of US-83 was added after 1957, but by 1962.

Attractions Along the Way: Eureka Pioneer Museum (Eureka); Fort Sisseton State Historical Park (southeast of Britton); Roy Lake State Park (southwest of Lake City); North-South Continental Divide (along Minnesota border east of Sisseton)

Links: Mr. Yamamoto's SD Highway 10 Page

Alignment: Jct. SD-1806/SD-273 to SD-47 south of Ft. Thompson

Multiplexing: Shared alignment with BIA-3 for 2 miles southeast from Lower Brule.

Lewis and Clark Trail: Jct. SD-1806 to Lower Brule.

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system; runs through the Lower Brule Indian Reservation.

Attractions Along the Way: Fort Defiance (west of Lower Brule)

Alignment:
Segment 1: Minnesota border(MN-269) north of Sherman to SD-48 northwest of Akron, IA
Segment 2: SD-50 west of Richland to Business I-29 at Elk Point (Franklin St.)

Distance: Segment 1: 75 miles. Segment 2: 5 miles.

Intersecting Interstates: I-90 at Brandon

Multiplexing: Shared alignment with SD-42 for 3 miles east from the eastern edge of Sioux Falls; with US-18 for 1 mile west of Canton.

Multi-lane Segments: Brandon

History and Notes: 1926 routing had SD-11 extending north through Sioux Falls and Dell Rapids (along current SD-115), and ending at US-14 near Elkton. New alignment north of Sioux Falls in place before 1938. Southern segment added around 1960.

Alignment on east side of Sioux Falls changed in early 1990's; segments 1 and 2 connected later in the 1990's.

An earlier (circa 1932) additional segment of SD-11 extended from Flandreau north to US-14, west of Elkton. This was changed to SD-13 by 1936.

Attractions Along the Way: Devil's Gulch (Garretson); Palisades State Park (Garretson); Newton Hills State Park (Fairview)

Links: Mr. Yamamoto's SD Highway 11 Page

Alignment: SD-34/SD-73 near the Ziebach/Meade County line to Cherry Creek

History and Notes: Part of the Bureau of Indian Affairs highway system; runs through the Cheyenne River Indian Reservation.

Alignment: Mound City to Minnesota border southeast of Sisseton

History and Notes: One of the original 1926 highway numbers, SD-12 was previously the "Glacier Trail". Designation changed to SD-10 by 1931, presumably to avoid confusion with nearby US-12.

Alignment: North Dakota border (US-12) northwest of Lemmon to Minnesota border (US-12) at Big Stone City

Distance: 317 miles.

Intersecting Interstates: I-29 in Roberts County.

Multiplexing: Shared alignment with SD-73 from Lemmon to Thunder Hawk; with SD-65 for 1 mile east of McIntosh; with SD-20 from 5 miles west of Mobridge to 4 miles south of Selby; with SD-1804 from Mobridge to 4 miles east of Mobridge; with US-83 from 3 miles northwest of Selby to 4 miles south of Selby; with SD-47 for 7 miles west from Bowdle; with SD-45 for 5 miles east from Ipswich; with US-281 through the west part of Aberdeen.

NHS: Entire route.

Multi-lane segments: 4-lane road from 6 miles west of Aberdeen to Groton, except for a short stretch near the Aberdeen Airport. The entire segment from Aberdeen to I-29 is scheduled to be upgraded to 4 lanes, as part of the "Eastern Dakota Expressway" project.

Lewis and Clark Trail: Mobridge to south jct. US-83

History and Notes: This road was originally called the "Yellowstone Trail". It was conceived by Ipswich businessman J.W. Parmley in 1912, as an initial desire for a good road from Ipswich to Aberdeen. The concept then quickly spread in both directions, and ended up as a national marked route. More information can be found here.

When US-12 was first marked in 1926, it was initially co-signed as SD-16.

Attractions Along the Way: Petrified Wood Park and Museum (Lemmon); Sitting Bull's Grave (southwest of Mobridge); Sacajawea Monument (southwest of Mobridge); Bangor Monument (south of Selby); Prayer Rock (Ipswich); Easton's Castle (Aberdeen); Dacotah Prairie Museum (Aberdeen)

Follow US-12 across: Washington, Idaho, Montana, North Dakota, Minnesota, Wisconsin, Illinois, Indiana, and Michigan
Historical routings across: Wyoming

Links: Mr. Yamamoto's SD US-12 Page; The Yellowstone Trail Organization

Alignment: Mina to US-12 north of Mina

Distance: 0.6 miles

History and Notes: Included in the SDDOT route logs, but not on the maps. Most likely an unnumbered route to link Mina to the state highway network.

Links: Mr. Yamamoto's SD Highway 12P Page

Alignment: Cherry Creek to SD-63 just north of the Cheyenne River

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system; runs through the Cheyenne River Indian Reservation.

Alignment: SD-34 south of Flandreau to US-14 north of Elkton

Distance: 28 miles

History and Notes: This route was originally a segment of SD-11, but was changed to SD-13 by 1936. At that time, it also was extended east from its original north end to Elkton, then north to US-14. This was due to a rerouting of US-14 in the early 1930's.

Links: Mr. Yamamoto's SD Highway 13 Page

Alignment: BIA-11 east of Howes to BIA-6 southeast of Red Scaffold

History and Notes: Part of the Bureau of Indian Affairs highway system; runs through the Cheyenne River Indian Reservation.

Alignment: Wyoming border (US-14) west of Spearfish to Minnesota border (US-14) near Elkton

Distance: 421 miles.

Intersecting Interstates: I-90 (co-signed from Wyoming border to Wall); I-29 at Brookings; I-190 at Rapid City.

Spurs and Alternates: Bypass US-14 east of Pierre and also north of Brookings.

Freeway: Wyoming border to Wall (co-signed with I-90).

NHS: Pierre to Minnesota border, Wall to Wyoming border.

Multiplexing: Shared alignment with I-90 from the Wyoming border to 1 mile east of Wall; with US-85 from Spearfish to 5 miles east of Spearfish; with SD-34 from Whitewood to Sturgis; with SD-79 from Sturgis to Black Hawk; with SD-63 from Midland to 4 miles west of Hayes; with SD-34 from SD-63 to Pierre; with US-83 from Ft. Pierre to 5 miles west of Blunt; with SD-45 through Miller; with US-281 from 3 miles northwest of Wolsey to 3 miles southeast of Wolsey; with US-81 for 4 miles south from Arlington.

Multi-lane segments: 10 mile stretch near Huron, as part of the "Eastern Dakota Expressway" project.

Lewis and Clark Trail: Pierre.

History and Notes: Originally called the "Black and Yellow Trail", the 1926 alignment had US-14 ending at Midland, with US-16 going northwest to the Wyoming border. This was changed in 1936, when US-16 was re-routed to extend west from Rapid City, and US-14 extended northwest along the old US-16 routing.

US Highways guru Robert Droz provides the flexible early history of US-14 in western South Dakota:

• Preliminary routing (1925-1926): West end at Jct US 16 in Midland.
• Final routing (1926-1927): Extended west to Philip Jct (south of Philip)
• 1928: Extended west along US 16 and US 85 to the SD-WY border
• 1929: Pulled back to Rapid City.
• 1932: Pulled back to Philip Jct.
• 1934: Extended to Rapid City.
• 1935: Extended to Wyoming line and west to Yellowstone National Park.

The segment from Rapid City to Box Elder was 4-laned by 1953. Part of this was incorporated into I-90.

Attractions Along the Way: High Plains Heritage Center (Spearfish); Matthews Opera House (Spearfish); Black Hills Passion Play (Spearfish); Sturgis Motorcycle Rally (Sturgis); Black Hills Nat'l Cemetery (Sturgis); Poker Alice House (Sturgis); Fort Meade Cavalry Museum (Sturgis); National Motorcycle Museum and Hall of Fame (Sturgis); Petrified Forest (east of Piedmont); Mount Rushmore National Memorial (southwest of Rapid City); The Journey Museum (Rapid City); Reptile Gardens (Rapid City); Air and Space Museum (Ellsworth Air Force Base); Wall Drug (Wall); Fort Pierre (Ft. Pierre); Verendrye Monument (Ft. Pierre); State Capitol (Pierre); South Dakota Discovery Center and Aquarium (Pierre); South Dakota National Guard Museum (Pierre); World War II Memorial (under construction in Pierre); Dakotaland Museum (Huron); South Dakota State Fair (Huron); Pyle House (Huron); Little Town on the Prairie (DeSmet); McCrory Gardens (Brookings); South Dakota Agricultural Heritage Museum (Brookings); South Dakota Art Museum (Brookings)

Follow US-14 across: Wyoming, Minnesota, Wisconsin, and Illinois

Links: Mr. Yamamoto's SD US-14 Page (includes Bypass US-14 information for Pierre and Brookings; US-14/83/SD-34 intersection reconstruction in Ft. Pierre (SD Dept. of Transportation)

Alignment: I-90 Exit 13 in Spearfish to SD-34 in Sturgis.

Distance: 44 miles.

Multiplexing: With US-85 from Cheyenne Crossing to Baltimore St. in Lead; with US-85 from Pine St. in Deadwood to US-85 jct. northeast of Deadwood.

History and Notes: Implemented in the late 1940's on an old alignment of SD-24, from Whitewood to US-85. By 1957, it extended west to Spearfish, then south to Cheyenne Crossing (US-85), replacing a segment of SD-89, and looping back to Deadwood via the northern Lead-Deadwood road. Around 1960, the east end was extended from Deadwood to Sturgis along the previous US-14, when US-14 was rerouted northwest from Sturgis along the projected I-90 alignment.

Attractions Along the Way: High Plains Heritage Center (Spearfish); Matthews Opera House (Spearfish); Black Hills Passion Play (Spearfish); Black Hills Mining Museum (Lead); Homestake Gold Mine (Lead); Broken Boot Gold Mine (Deadwood); Mt. Moriah Cemetery (Deadwood); Sturgis Motorcycle Rally (Sturgis); Black Hills Nat'l Cemetery (Sturgis); Poker Alice House (Sturgis); Fort Meade Cavalry Museum (Sturgis); National Motorcycle Museum and Hall of Fame (Sturgis)

Alignment: Spearfish, I-90/US-85 intersection to Yankee St.

Distance: 0.9 miles.

History and Notes: Included in the SDDOT route logs, but not on the maps. It is a former alignment of US-14/US-85 in the area.

Alignment: Old US-81 (near I-29 exit 213) to I-29 west of Toronto.

Distance: 78 miles.

Intersecting Interstates: I-29 west of Wilmot and west of Toronto.

Multiplexing: Shared alignment with SD-20 from 8 miles south of Milbank to 4 miles west of Revillo; with US-212 from 3 miles south of the Grant/Deuel County line to 3 miles north of Altamont; with SD-28 from I-29 to 2 miles west of Toronto.

History and Notes: Originally, SD-15 ran the entire north-south length of South Dakota. It mostly followed the future US-77, which had been designated by 1931. It then went north from Milbank, then west to Wilmont, and north to Sisseton. SD-15 then went north to Hammer along US-81. From there, it went west to Claire City, then north to meet ND-18. By 1932, the only segment remaining was US-12 to the North Dakota line.

In the early 1950's, changes were made to the southern end. SD-15 was rerouted so the south end was at US-12/77 at Milbank; it then went north to Hartford Beach, then west through Wilmot to US-81, before heading north again; the old alignment from Wilmot to US-12 became SD-15A. In 1976, the west (north) end was truncated to US-81; the segments of SD-15 near the North Dakota border became SD-106 and part of a realigned SD-25. After US-77 was decommissioned in the early 1980's, SD-15 then extended along the former's alignment south from Milbank, to the present end at I-29 west of Toronto.

Attractions Along the Way: Hartford Beach State Park (east of Wilmot).

Links: Mr. Yamamoto's SD-15 Page

Alignment: Wilmot to Marvin

History and Notes: This designation was established in the early 1950's on the old route of SD-15. Designation changed to SD-123 in 1976.

Alignment: US-12 at Big Stone City to SD-15 near Hartford Beach

History and Notes: One of two branches off SD-15, SD-15Y was designated in the early 1960's. It was renumbered as SD-109 in 1976.

Alignment: Lemmon to Ortonville, MN

History and Notes: Part of the "Yellowstone Trail", SD-16 was co-signed as US-12 in 1926. SD-16 designation dropped in the 1930's.

Alignment: I-90 at northeast edge of Rapid City to Jct. SD-79/BYPASS US-16 at southeast edge of Rapid City

History and Notes: Designated in 1991. Stretch of highway from the old BYPASS US-16 to I-90 was designated as an extention of BYPASS US-16 in 1994, eliminating SD-16B.

Alignment: I-90 near downtown Rapid City to Wyoming border (US-16) southeast of Newcastle, WY

Distance: 74 miles.

Intersecting Interstates: I-90 in Rapid City.

Freeway Segments: Main St. to I-90 in Rapid City (co-sign with I-190).

NHS: Entire route

Multi-lane segments: "Mount Rushmore Road", from south side of Rapid City to Keystone.

Spurs and Alternates: Bypass US-16 on southeast side of Rapid City; Business US-16 in Hill City.

Multiplexing: Shared alignment with I-190 in Rapid City, and with US-385 from Custer to east of Hill City.

History and Notes: Formerly extended east to Minnesota border, parallel to the current I-90 (Rapid City to Alexander), SD-42 (Alexander to Valley Springs), and SD-263 (Valley Springs to Minnesota border). Segment east of Sioux Falls decommissioned in 1979; remainder from Sioux Falls to Rapid City decommissioned in 1980. Several unposted highway numbers now make up most of the Rapid City to Plankinton segment (see SD-230, SD-248, and SD-258).

One of the original names of this route was the Custer Battlefield Highway.

1926 alignment had US-16 following the current I-90 to the Wyoming border, as US-14 ended at Midland. US-16 was also co-signed as SD-24 from the Wyoming border to Sturgis. In eastern South Dakota, US-16 followed current SD-38 through Sioux Falls into Minnesota; the segment east of Fulton was co-signed as SD-40. Routing was changed in 1936, to extend US-16 west from Rapid City; the eastern portion was aligned by 1953 to the (current) SD-42/SD-264 alignment.

In 1998, when legislation was first introduced in the South Dakota legislature to authorize the US-16 Bypass in Rapid City, it was proposed to extend east to Box Elder, along the old US-14/US-16 alignment. This was modified to the present configuration before the legislation was approved.

Attractions Along the Way: The Journey (Rapid City); Black Hills Caverns (Rapid City); Bear Country USA (southwest of Rapid City); Black Hills Reptile Gardens (southwest of Rapid City); Mount Rushmore National Memorial (Keystone, via ALT-16); Beautiful Rushmore Cave (Keystone, via ALT-16); Borglum Historical Center (Keystone, via ALT-16); Harney Peak, highest point in South Dakota (south of Hill City); 1880 Train (Hill City); Crazy Horse Monument (north of Custer); Jewel Cave National Monument (west of Custer); Four Mile Old West Town (west of Custer); National Museum of Woodcarving (west of Custer); Custer County 1881 Courthouse (Custer); Flintstones Bedrock City (Custer)

Follow US-16 across: Wyoming
Historical routings across: Minnesota, Wisconsin, and Michigan

Links: Mr. Yamamoto's South Dakota US-16 Page.

Alignment: Wall to US-16 west of Kadoka

History and Notes: This route through the Badlands was originally part of SD-40. The US-16A alignment was applied between 1944 and 1948. By 1962, the east end was truncated to Cactus Flats, at the eastern extent of I-90 construction in the area (exit 131). In 1980, the route was redesignated as SD-240 after mainline US-16 was decommissioned east of Rapid City.

Alignment: Custer (US-16/US-385), east then north, to US-16 north of Keystone

Distance: 39 miles.

History and Notes: Designated between 1944 and 1948, along what is now the concurrent US-385 alignment; US-16 at the time went south through Keystone, then west along SD-36 to Custer before continuing west to Wyoming. Between 1953 and 1957, US-16 was rerouted onto what had been the alternate route, and the segment of mainline US-16 from Keystone to Custer via SD-36 became the new alternate. This configuration remains in place today.

Attractions Along the Way: Mount Rushmore National Memorial (Keystone); Big Thunder Gold Mine (Keystone); Beautiful Rushmore Cave (Keystone); Custer State Park (east of Custer); Gordon Stockade (east of Custer); Cosmos of the Black Hills (north of Keystone)

Alignment: Peever to Milbank.

History and Notes: Original 1926 routing. Was renumbered as part of SD-15 by 1932. After a rerouting of SD-15 in the early 1950's, the segment of this road between Wilmot and US-12 became SD-15A, then was changed to SD-123 in 1976. The Peever to Wilmot segment has been unnumbered since.

Alignment: SD-42 west of Sioux Falls to SD-44 at Lennox.

Distance: 15 miles.

History and Notes: Designation in place by 1932. The original alignment continued south to SD-46 near Centerville; this segment (south of SD-44) was decommissioned in the 1990's.

Attractions Along the Way: Wild Water West Waterpark (west of Sioux Falls).

Links: Mr. Yamamoto's SD-17 Page.

Alignment: Montana border near Camp Crook to Mobridge.

History and Notes: Original designation from 1926. Changed to SD-8 by 1935, then to SD-20 between 1965 and 1970.

Alignment: Wyoming border (US-18) west of Edgemont to Iowa border (US-18) at Canton

Distance: 448 miles.

Intersecting Interstates: I-29 (co-signed for 3 miles) west of Canton.

NHS: Wyoming border to Pickstown.

Freeway: 3-mile segment west of Canton (co-signed with I-29).

Multi-lane Segments: Hot Springs to Jct. US-385.

Spurs and Alternates: BYPASS US-18 along the south side of Hot Springs.

Multiplexing: Shared alignment with US-385 from Hot Springs to Oelrichs; with SD-73 from Martin to 5 miles south of Patricia; with US-83 for 3 miles west from Mission; with SD-44 from Jordan Junction to Winner; with US-183 from Jordan Junction to Colome; with SD-47 from Gregory to Burke; with US-281 from near the Nebraska border to 6 miles south of Armour; with SD-50 from Lake Andes to 4 miles east of Ravinia; with SD-19 for 1 mile between Hurley and Viborg; with I-29 for 3 miles southwest of Worthing; with SD-11 for 1 mile west of Canton.

Lewis and Clark Trail: Gregory to Pickstown.

History and Notes: Was not part of the original 1926 highway plan, but was designated by 1931.

Minor realignments have been made over the years. This includes the segment southeast of Hot Springs (road straightened out); the segment from Pine Ridge to Batesland (segment going north to Wounded Knee was bypassed to the south); Parmlee to Mission (new alignment to bypass Rosebud); Bonesteel to near Armour (original alignment was flooded by the creation of Lake Francis Case).

In this flooded segment, the original US-18 curved northeast from Bonesteel, along Gregory CR 61. At the old town of Wheeler, it headed roughly to Lake Andes. The current alignment in this area is due east from Fairfax (along old SD-54), then northeast through Pickstown (created after the lake was formed in the 1950's), then north to Lake Andes. The old bridge at Wheeler was moved north to Chamberlain, to serve as an additional pair of lanes for US-16.

The segment of US-18 that is multiplexed with US-385 (Oelrichs to east of Hot Springs) is part of the future "Heartland Expressway", which will link Denver and Rapid City.

Attractions Along the Way: Mammoth Site (Hot Springs); Wounded Knee Battle Site (northeast of Pine Ridge); Fort Randall Dam (Pickstown); Fort Randall (southwest of Pickstown); Heritage House Museum (Canton)

Follow this road across: Wyoming, Iowa, and Wisconsin

Links: Mr. Yamamoto's US-18 Page

Alignment: "A" St. and 2nd Ave. in Edgemont.

Distance: 0.8 miles.

Multiplexes: Shared alignment with SD-471 from US-18 to 2nd Ave.

History and Notes: An unmarked road, maintained by SDDOT, probably on an old alignment of US-18 through town.

Alignment: SD-34 southeast of Madison to Nebraska border ( NE-15) south of Vermillion.

Distance: 100 miles.

Intersecting Interstates: I-90 near Humboldt.

Multi-lane Segments: First 2 miles southeast of Madison.

Multiplexing: Shared alignment with SD-38 for 1 mile west from Humboldt; with SD-42 from Union Center to Pumpkin Center; with SD-44 for 3 miles southeast from Parker; with US-18 for 1 mile between Hurley and Viborg; with SD-46 from 4 miles east of Irene to 2 miles south of Centerville.

History and Notes: Unchanged from original 1926 routing, with two exceptions. SD-19 previously went into Centerville along the current SD-19A; this was changed around 1950. In November 2001, SD-19 was extended south from Vermilion, when a new bridge to Nebraska was opened.

Attractions Along the Way: Spirit Mound (north of Vermillion); Shrine to Music, W.H. Over State Museum, and Austin-Whittemore House (all in Vermillion)

Links: Mr. Yamamoto's SD-19 Page

Alignment: US-212 between Parade and Ridgeview to jct. BIA-8/BIA-9 southeast of Parade

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system; runs through the Cheyenne River Reservation.

Alignment: SD-19, 6 miles west of Centerville, to SD-19/SD-46, 2 miles south of Centerville.

Distance: 8 miles.

History and Notes: One of the few remaining "suffixed" state routes. This was originally part of mainline SD-19, but was changed when SD-19 was rerouted west and south of Centerville around 1950.

Links: Mr. Yamamoto's SD-19A Page

Distance: Segment 1: 393 miles. Segment 2: 39 miles.

Intersecting Interstates: I-29 near South Shore.

Multiplexing: Shared alignment with US-85 for 2 miles south from Buffalo; with SD-79 for 5 miles east from Reva; with SD-73 from Meadow Corner to 3 miles west of Coal Springs; with SD-65 from 1 mile west of the Dewey/Ziebach County line to Isabel; with SD-63 from 7 miles west of Timber Lake to 4 miles west of Trail City; with US-12 from 5 miles northwest of Mobridge to 4 miles south of Selby; with US-83 from 4 miles northwest of Selby to the Walworth/Potter County line; with SD-47 from 1 mile west of Hoven to 3 miles south of Hoven; with SD-45 for 2 miles west of Cresbard; with SD-37 for 3 miles south from Conde; with SD-15 from 8 miles south of Milbank to 3 miles west of Revillo.

Multi-lane Segments: Lake Kampeska to Watertown.

Unpaved Segments: Montana border to Camp Crook.

Lewis and Clark Trail: Mobridge to Walworth/Potter County line.

History and Notes: SD-20 is continuous from the Montana border to Watertown (US-212). From there, it has a break before restarting at old US-81 west of South Shore, passing through Revillo and linking into MN-40. The 1975 Rand McNally atlas showed that SD-20 linked these two roads by a multiplex with along (old) US-81 from Watertown to west of South Shore, but the state highway map by 1981 showed it as separated.

Segment from Montana border to Mobridge was originally SD-18, then changed to SD-8 by 1935, with the designation changed to a SD-20 extension in the late 1960's.

The original west end of SD-20 was at SD-45 south of Ipswich. Between 1944 and 1948, the route was extended to Akaska, just west of US-83 in Walworth County. In the late 1960's, the short stub into Akaska was designated as SPUR SD-20, as SD-20 was extended north to US-12, over to Mobridge, then westward replacing SD-8. The spur was renumbered as SD-144 in 1976.

The original east end of SD-20 was at Watertown. In the early 1950's, the segment between US-81 and US-77 (current SD-15) was designated. By 1957, SD-20 was then extended south to 2 miles north of the Deuel County line, then east through Revillo to the Minnesota border. This alignment remains in place today.

Attractions Along the Way: 1876 Slim Buttes Battle Sites (Reva); Sitting Bull's Grave (southwest of Mobridge); Sacajawea Monument (southwest of Mobridge); Bangor Monument (south of Selby); Cathedral on the Prairie (Hoven); Redlin Art Center (Watertown); Arthur Mellette House (Watertown).

Links: Mr. Yamamoto's SD-20 Page.

Alignment 1: SD-15 (old US-77) west of Revillo to Minnesota border east of Revillo
Alignment 2: SD-20/US-77 (present SD-15) junction east to Minnesota border

History and Notes: Designated around 1970, SD-20A initially used the present SD-20 alignment through Revillo. This was moved to the current SD-158 alignment a few years later. Eliminated in the late 1970's, and later designated SD-158.

Alignment: Akaska to US-83/SD-20 junction east of Akaska.

History and Notes: In the early 1950's, this was the start of mainline SD-20. It was changed to SPUR SD-20 between 1965 and 1970. This spur was renumbered as SD-144 in 1976.

Alignment: Lake Norden (SD-28) to US-81/SD-28 east of Hayti.

Distance: 9.5 miles.

History and Notes: 1926 alignment had SD-21 co-signed with the newly-assigned US-81 the entire length of South Dakota. Only the current alignment was left by 1936.

Attractions Along the Way: South Dakota Amateur Baseball Hall of Fame (Lake Norden).

Links: Mr. Yamamoto's SD-21 Page

Alignment: Walker (US-12) to SD-63 south of McLaughlin.

Unpaved Segments: Bullhead to SD-63.

History and Notes: Part of the Bureau of Indian Affairs highway system; runs through the Standing Rock Indian Reservation.

Alignment: Hazel to Minnesota border (MN-68) west of Canby, MN.

Distance: 53 miles.

Intersecting Interstates: I-29 west of Clear Lake.

Multiplexing: Shared alignment with US-81 for 2 miles west of Castlewood.

History and Notes: 1926 highway maps had SD-22 extending west all the way to the Wyoming border, following what is now US-212. The present alignment was in place by 1948, and included a north-south segment from Hazel to US-212. This segment was eliminated in the 1990's.

Links: Mr. Yamamoto's SD-22 Page

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

History and Notes: Designated between 1965 and 1971, this route was changed to SD-101 in 1976.

Alignment: Claire City to US-212 west of Watertown.

History and Notes: Original 1926 route. By 1936, the only part left was along the west shore of Lake Kampeska. SD-25 was later realigned along much of the old route. The remaining SD-23 segment was redesignated as SD-139 in 1976.

Alignment: Current Jct. SD-20 near Meadow to Wyoming border west of Belle Fourche.

History and Notes: Designation from 1926 followed path of current SD-73 southward to Howes, then west along current SD-34 to Sturgis, and followed US-16 (later US-14) to Whitewood. By 1936, the north-south segment was made part of SD-73. Between 1944 and 1948, SD-24 was extended northwest from Whitewood to Belle Fourche, and by 1953, the road extended west from Belle Fourche to the Wyoming line. The route was redesignated as part of SD-34 by 1960.

Alignment: Belle Fourche to Whitewood (west of Sturgis).

History and Notes: Designated around 1940, and decommissioned by 1950 as mainline SD-24 was rerouted onto this alignment. By 1960, it was reestablished as part of SD-34.

Alignment:
North segment: North Dakota border (ND-18) north of Claire City to SD-42 south of Emery.
South segment: US-18 west of Olivet to SD-50 northwest of Tabor.

Distance: North segment: 185 miles. South segment: 22 miles.

Intersecting Interstates: I-90 south of Farmer.

Multiplexing: (Segment 1) Shared alignment with SD-10 for 1 mile east from Lake City; with US-212 for 1 mile west of Henry; with SD-28 for 3 miles just north of the Clark/Kingsbury County line; with SD-34 from 1 mile west of Howard to 1 mile east of Roswell.

History and Notes: Original 1926 alignment had the south end of SD-25 ending at Howard. From current SD-262, the SD-25 designation was applied northward as construction of the road occurred; the north part of this segment was at Farmer by 1971, Epiphany by 1977, and SD-34 by 1981.

Originally, SD-25 went through Howard, but was shifted west 1 mile in the early 1950's. The Miner County (SD) Pioneer newspaper on July 25, 2002 included a clip from the newspaper in summer 1952 about the subject:

A large crowd was on hand at the courthouse in Howard when the State Highway Commission held the hearing on the moving of Highway 25 to one mile west of Howard. After discussions pro and con, Mrs. Theo Sandler asked that a vote be taken of those present. In the voting, 53 voted against the proposed change and 12 voted for the change. About 20 percent did not vote.

On the north end, SD-25 took a zig-zag route north from De Smet; in 1932, it went through Clark to Webster, then west about 15 miles before heading north to Britton and the North Dakota line northeast of Kidder. In the mid 1950's, the route was realigned so it went straight north from De Smet to US-212 9 miles east of Clark, then after a 1 mile jog east, north to Webster, before resuming the previous alignment to North Dakota. In 1976, SD-25 was shifted east to use old SD-23 from Webster to Lake City; it then curved northeast through Veblin and north again at Hammer (on former SD-15).

The current southern segment was the former SD-35, and was renumbered to SD-25 in 1976.

Attractions Along the Way: Little Town on the Prairie (DeSmet)

Links: Mr. Yamamoto's SD-25 Page

Alignment: SD-47 north of Highmore to US-281 south of Redfield.

Distance: 50 miles.

Multiplexing: Shared alignment with SD-45 for 1 mile east of Polo.

History and Notes: An extension of SD-26 from Oneida (US-83) to US-281 was planned in the late 1970's; although a road is there, it does not carry the SD-26 designator.

Segment between SD-45 and SD-47 was added between 1957 and 1962.

Links: Mr. Yamamoto's SD-26 Page

Alignment: Olivet to near Tabor.

History and Notes: Original 1926 alignment in southern South Dakota. Was made part of SD-35 by 1936. Currently is the southern end of SD-25.

Alignment: North Dakota border (ND-32) near Havana, ND, to US-12 southeast of Andover, SD.

Distance: 52 miles.

Multiplexing: Shared alignment with SD-10 for 6 miles east from Britton.

History and Notes: Designated in 1976. Was previously the original northern end of SD-25.

Links: Mr. Yamamoto's SD-27 Page

Alignment: Pennington County border south of Scenic to US-18 south of Wounded Knee.

Multiplexing: Shared alignment with BIA-2 from Rockyford to Sharps Corner.

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system; runs through the Pine Ridge Indian Reservation.

Attractions Along the Way: Wounded Knee National Historic Site (Wounded Knee).

Alignment: US-281 north of Bonilla to Minnesota border (MN-271) east of Astoria

Distance: 109 miles.

Intersecting Interstates: I-29 west of Toronto.

Multiplexing: Shared alignment with SD-25 for 3 miles between Willow Lake and Bryant; with US-81 for 1 mile north from Alsville; with SD-15 from I-29 to 2 miles west of Toronto.

History and Notes: SD-28 originally ended at SD-25 near Willow Lake. Extension westward was made in the mid 1950's. A further extension west to SD-45 may have been marked briefly, but was not indicated as such by 1970.

Attractions Along the Way: South Dakota Amateur Baseball Hall of Fame (Lake Norden).

Alignment: Manderson (BIA-33) to Wounded Knee (BIA-27).

History and Notes: Part of the Bureau of Indian Affairs (BIA) highway system; runs through the Pine Ridge Indian Reservation.

Attractions Along the Way: Wounded Knee National Historic Site (Wounded Knee).

Alignment: North Dakota border (I-29) north of Victor to Iowa border (I-29) at North Sioux City.

Distance: 249 miles.

Intersecting Interstates: I-90 and I-229, both in Sioux Falls.

NHS: Entire length.

Business Routes: Spur I-29 in Sioux Falls, Loop I-29 in Elk Point and North Sioux City.

Multiplexing: Shared alignment with US-81 from the North Dakota border to Watertown; with US-18 for 3 miles southwest of Worthing.

History and Notes: When the Interstate system was being planned in the 1950's, I-29 was only planned to run from Sioux Falls southward. When the extension northward was proposed, it was originally to run in Minnesota, but was shifted westward due to efforts by Sen. Francis Case. In addition, early planning of this segment of I-29 had the route passing just east of Kranzburg, or about 9 miles east of Watertown. A past president of the Watertown Chamber of Commerce contaced C.L. Chase, a member of the Democratic National Committee, in an effort to get I-29 routed closer to Watertown. The effort was successful; the westward alignment became known locally as the Chase Bend.

Historical construction of I-29:

• 1962: Segments from Sioux City to SD-50, and southern US-18 junction to I-90, complete.
• 1969: Completed from SD-34 to the Iowa border.
• 1971: Additional segment from Brookings to SD-34 complete. Alignment still proposed northward to North Dakota.
• 1980: Segment from Peever to Victor under construction; remainder was completed.
• 1985: Entire route complete.

Reconstruction work has begun on I-29 through Sioux Falls. This involves rebuilding the Madison St. to I-90 segment as 6 lanes, building an interchange at Benson Rd., reconstructing the Russell St. interchange to remove the southbound left exit and changes to Russell St. itself, and reconstruction of the SD-38 interchange. More information can be found here.

Attractions Along the Way: Redlin Art Center (Watertown); Arthur Mellette House (Watertown); McCrory Gardens (Brookings); South Dakota Art Museum (Brookings); South Dakota Agricultural Heritage Museum (Brookings); Great Plains Zoo and Delbridge Museum (Sioux Falls); Old Courthouse Museum (Sioux Falls); Washington Pavilion of Arts and Sciences (Sioux Falls); USS South Dakota Memorial (Sioux Falls); Union County State Park (south of Beresford)

Follow I-29 across: North Dakota, Iowa, and Missouri

Links: Exit Listings for I-29, I-29 Reconstruction Information in Sioux Falls (South Dakota Department of Transportation).

Alignment: Wyoming border southwest of Lead to Minnesota border near Elkton.

History and Notes: Original 1926 route. Segment from Wyoming border to Sturgis was a co-sign of US-85; Sturgis to Midland segment was a co-sign of SD-65; Segment from Hayes to Elkton was a co-sign of US-14. Entire route was eliminated by 1936.

Alignment: I-29 at exit 140 (west of White) to Minnesota border (MN-19).

Distance: 17 miles.

Intersecting Interstates: I-29 west of White.

History and Notes: Designated around 1960, this route also extended west to US-81, then north a couple miles, then west again to SD-25 north of DeSmet. This western segment was removed by 1971.