Cities and Towns in Sully County, South Dakota
Founded in 1873, Sully County is one of 66 counties in the state of South Dakota. Historically, Sully County was formed from Potter County. The city of Onida is the county seat. With FIPS code of 119, Sully County has a population of 1,476 and area of 1,007 square miles (2,608 km²).
List of all cities in Sully County, SD alphabetically
| City/Town | Postal Code | Area Code |
| Agar, SD | 57520 | 605 |
| Kasper, SD | 57564 | 605 |
| Onida, SD | 57564 | 605 |
Major Cities and Towns in Sully County, South Dakota
Onida, South Dakota
Location and History
Onida, the county seat of Sully County, is located in the central part of South Dakota, about 15 miles west of the Missouri River and 35 miles southeast of Pierre. Onida was founded in 1880, initially as a railroad town. The town’s name is derived from the Lakota Sioux word “Onida,” which means “the one who seeks,” reflecting the region’s Native American heritage. The arrival of the Chicago and North Western Railway was a significant factor in the development of Onida, as it became a transportation hub for the surrounding agricultural area. Onida quickly grew as a service center for local farmers, ranchers, and traders. While its population has remained relatively small, Onida has maintained its role as an important administrative and commercial center for the surrounding rural areas. The town has a rich agricultural history, with the surrounding fields providing crops such as wheat, corn, and soybeans, as well as cattle and livestock.
Major Schools and Landmarks
Onida is served by the Sully Buttes School District, which includes Sully Buttes High School, Sully Buttes Middle School, and several elementary schools. The district is known for its strong academic programs and extracurricular activities, which include sports teams and community involvement. Major landmarks in Onida include the Sully County Courthouse, a historic building that serves as the administrative center for the county. Onida also features several parks, including the Onida City Park, which has a walking trail, picnic areas, and sports fields. The Missouri River is nearby, providing opportunities for boating, fishing, and wildlife viewing. One of the town’s annual highlights is the Onida Fair, which celebrates the agricultural heritage of the region with events such as rodeos, concerts, and livestock shows. Onida also boasts a small but active downtown area with local businesses that reflect the town’s rural charm and tight-knit community.
Key Statistics
- Area: 0.5 square miles
- Population: 700 (2020 census)
- Zip Codes: 57564
- Latitude: 44.5404° N
- Longitude: 99.2206° W
Agar, South Dakota
Location and History
Agar is located in the southeastern part of Sully County, South Dakota, approximately 20 miles northeast of the Missouri River and 40 miles east of Onida. Agar was founded in the early 1900s and named after Agar, a small town in Ireland. The town developed as a farming and ranching community and was once a major railroad stop along the Chicago and North Western Railway. Over time, the railroad’s role in the town diminished, but Agar’s rural charm and agricultural heritage have remained central to its identity. With a small but dedicated population, Agar continues to serve the surrounding farming community. The town’s economy is still largely based on agriculture, with farmers growing a variety of crops and raising livestock. The community maintains a quiet, small-town atmosphere, offering a peaceful rural lifestyle with close connections to the land.
Major Schools and Landmarks
Agar is served by the Sully Buttes School District, with students attending schools in Onida or nearby communities. Although small, the school district offers quality education and extracurricular activities for students of all ages. Key landmarks in Agar include the Agar Community Center, which serves as a gathering place for social events and meetings. The town is also home to several parks and recreational areas, including the Agar City Park, where residents can enjoy outdoor activities such as picnicking, sports, and walking. Agar’s proximity to the Missouri River offers additional opportunities for boating, fishing, and wildlife observation. The area surrounding Agar is known for its scenic beauty, with wide open fields and rolling hills that provide a peaceful backdrop for residents and visitors alike. Despite its small size, Agar remains a welcoming community with a deep connection to its agricultural roots and its natural surroundings.
Key Statistics
- Area: 0.4 square miles
- Population: 100 (2020 census)
- Zip Codes: 57520
- Latitude: 44.4731° N
- Longitude: 99.3934° W
Harrold, South Dakota
Location and History
Harrold is a small town located in the southeastern part of Sully County, South Dakota, near the junction of U.S. Highway 83 and South Dakota Highway 34. The town was founded in the late 1800s and was named after an early settler, Harrold E. Nash. Harrold’s early economy was based on agriculture and ranching, with settlers taking advantage of the fertile soil and open prairie for farming and cattle grazing. The town was once a bustling community with local businesses and a strong connection to the surrounding farming industry. While its population has declined over the years, Harrold remains a key part of Sully County’s agricultural landscape, and its residents continue to work in farming, ranching, and related industries. The town’s central location along major transportation routes has also contributed to its lasting presence in the region.
Major Schools and Landmarks
Harrold is part of the Sully Buttes School District, which provides educational services to the surrounding area. Students from Harrold attend schools in Onida or other nearby communities. While the town does not have many large-scale landmarks, it is home to the Harrold City Park, which offers recreational opportunities such as picnicking, sports, and family gatherings. The park is a central gathering spot for residents, and it is frequently used for local events. Harrold’s rural location also provides residents with access to outdoor activities such as hunting, fishing, and hiking in the nearby prairie and river landscapes. The town’s small size and rural setting make it an ideal location for those who enjoy a quiet, country lifestyle while still being within reach of the services and amenities found in nearby towns like Onida.
Key Statistics
- Area: 0.3 square miles
- Population: 50 (2020 census)
- Zip Codes: 57536
- Latitude: 44.3580° N
- Longitude: 99.1611° W