Deuel County is a county in South Dakota, United States, on the state’s eastern edge along the Minnesota border. It had a population of 4,295 at the 2020 census and covers 637 square miles (1,650 km2), centred near 44°46′N 96°40′W.
Clear Lake is the county seat, and its postal code is 57226. The county has two cities and five incorporated towns, plus several unincorporated communities, and sits in the Central time zone.
Towns & Villages in Deuel County
Deuel County has seven incorporated places — two cities and five towns — along with a handful of unincorporated communities that appear on maps and older place lists but carry no municipal government. Type key: City = incorporated city; Town = incorporated town; Unincorp. = unincorporated community, not a legal municipality.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Clear Lake | City · seat | — | 57226 |
| Gary | City | — | 57237 |
| Astoria | Town | — | 57213 |
| Brandt | Town | — | 57218 |
| Goodwin | Town | — | 57238 |
| Toronto | Town | — | 57268 |
| Altamont | Town | — | 57213 (Astoria) |
| Bemis | Unincorp. | — | — |
| Johnsonville | Unincorp. | — | — |
| Moritz | Unincorp. | — | — |
| Tunerville | Unincorp. | — | — |
ZIP Codes
- 57226 — Clear Lake
- 57237 — Gary
- 57213 — Astoria (also serves Altamont)
- 57218 — Brandt
- 57238 — Goodwin
- 57268 — Toronto
Bemis, Johnsonville, Moritz, and Tunerville are unincorporated rural communities without their own post offices and are served by the nearest listed ZIP code.
Geography
Deuel County lies on South Dakota’s eastern boundary, in the rolling prairie of the state’s Coteau des Prairies upland, with terrain sloping toward the northeast. Farmland covers most of the county; the highest point, 1,936 feet above sea level, sits on the upper west border. The county totals 637 square miles, of which 623 square miles are land and 14 square miles — about 2.2 percent — are water, held mostly in small glacial lakes scattered across the rolling upland left behind by the last ice age.
Deuel County borders Grant County to the north, Codington County to the northwest, Hamlin County to the southwest, and Brookings County to the south. Three Minnesota counties lie across the state line to the east.
Demographics
Deuel County had 4,295 residents at the 2020 census. Clear Lake and Gary are the county’s two largest communities. Household income in the county runs below the South Dakota median of $71,810, typical of a farming-dependent rural county. Population density works out to roughly 6.9 people per square mile of land.
Economy & Local Life
Agriculture drives the local economy — corn, soybeans, and cattle on the county’s rolling farmland. Clear Lake, the seat, holds the county’s main services, schools, and government offices, including the Deuel County Courthouse and the local school district. Grain elevators and farm-supply businesses anchor the smaller towns along the rail corridor and Interstate 29. Lake Cochrane, a popular regional recreation spot near Astoria, draws boaters and anglers from across the region in summer, and several smaller lakes dot the county’s rolling terrain.
History
Deuel County was created by the Dakota Territory legislature in 1862 and organized as a county government in 1878. It was named for Jacob Deuel, a territorial legislator that same year. Settlement followed the railroad through the 1880s, with towns platted at sidings along what became the Chicago, Milwaukee, St. Paul and Pacific line. Clear Lake, platted in 1884, grew into the county’s trade and government center, while Gary and Toronto developed as smaller rail-siding towns serving the surrounding farmland. Like much of eastern South Dakota, the county’s early population was heavily Scandinavian and German immigrant farm families, a heritage still visible in local church and community names.
Getting There
Interstate 29 runs north-south through the county, with U.S. Highway 212 and South Dakota Highways 15, 22, 28, and 101 providing local connections.
- Watertown — 25 miles northwest
- Brookings — 25 miles south
- Sioux Falls — 75 miles south
- Minneapolis, Minnesota — 190 miles east
Watertown Regional Airport is the nearest commercial airport.
Frequently Asked Questions
Where is Deuel County, South Dakota?
It sits on South Dakota’s eastern border, adjoining Minnesota, along Interstate 29.
What is the population of Deuel County?
Deuel County had 4,295 residents at the 2020 census.
How big is Deuel County?
The county covers 637 square miles (1,650 km2), including 14 square miles of water.
What is the county seat of Deuel County?
Clear Lake is the county seat and largest city.
How many towns are in Deuel County?
Seven incorporated places — two cities (Clear Lake, Gary) and five towns (Astoria, Altamont, Brandt, Goodwin, Toronto) — plus several unincorporated communities.
What ZIP codes are in Deuel County?
Six ZIP codes serve the county: 57226 (Clear Lake), 57237 (Gary), 57213 (Astoria), 57218 (Brandt), 57238 (Goodwin), and 57268 (Toronto).
Why is Deuel County named Deuel?
It was named for Jacob Deuel, a Dakota Territory legislator in 1862.
More counties in this state: Towns and villages in South Dakota.