List of South Dakota numbered highways on:
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South Dakota's state highways were assigned in a numbering pattern that followed that of the 
U.S. Highways
The United States Numbered Highway System (often called U.S. Routes or U.S. Highways) is an integrated network of roads and highways numbered within a nationwide grid in the contiguous United States. As the designation and numbering of these h ...
followed upon their inception. East–west highways carried even numbers and increased from North to South
– while north–south highways carried odd numbers and increased from east to west. This holds true only for two-digit highways. Three-digit highways follow the odd–even routing, but do not sequentially remain near a "parent" route as a spur or alternate route, instead being more independent of any parent two-digit route.
State highways
See also
*References
{{US state highways State