South Dakota spending, because of the proximity of many tourist attractions in the Black Hills and Ellsworth Air Force Base. The next eight largest cities in the state, in order of descending 2010 population, are Aberdeen (26,091), Brookings (22,056), Watertown (21,482), Mitchell (15,254), Yankton (14,454), Pierre (13,646), Huron (12,592), and Vermillion (10,571). Pierre is the state capital, and Brookings and Vermillion are the locations of the state's two largest universities (South Dakota State University and University of South Dakota, respectively). With a population of about 14,000, Pierre is the second smallest state capital in the United States. Of the ten largest cities
South Dakota Highway 15 1976, when many of the suffixed state routes were eliminated, this route was redesignated as SD 123. South Dakota Highway 15Y (SD 15Y) was a short state highway in the northeastern part of the U.S. state of South Dakota. It was established in the early 1960s, from US 12 in Big Stone City to SD 15 southwest of Shady Beach. In 1976, it was redesignated as SD 109. South Dakota Highway 15 South Dakota Highway 15 (SD 15) is a state highway in the northeastern part of the U.S. state of South Dakota. It connects Clear Lake, Milbank, and Wilmot.