South Dakota Highway 115

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Highway 115
Route of SD 115 (in red)
Route information
Maintained by SDDOT
Length	40 mi (64 km)
Existed	1980–present
Major junctions
South end	US 18 west of Canton
Major intersections	I-229 / I-229 Dwtn. in Sioux Falls I-29 Dwtn. in Sioux Falls I-90 in Sioux Falls
North end	I-29 west of Dell Rapids
Location
Country	United States
State	South Dakota
Counties	Lincoln Minnehaha
Highway system
South Dakota State Trunk Highway System Interstate US State
← SD 109 → SD 123

South Dakota Highway 115 (SD 115) is a 40-mile (64 km) state highway in Lincoln and Minnehaha counties in South Dakota, United States, that was created from the routing of US 77, "Old 77", when its alignment was moved west to become Interstate 29 around 1980 and SD 15's route from US 18 to Sioux Falls. SD 115 routes from its intersection with US 18 about 13 miles (21 km) south of Sioux Falls to Interstate 29 three miles west of Dell Rapids. It is about 40.5 miles (65.2 km) in length.

SD 115 was designated a POW/MIA Memorial Highway in 2000. The segment south of Sioux Falls to US 18 was originally designated part of the Custer Battlefield Highway when it was designated SD 15.