Darke County, Ohio

Darke County is a county in Ohio, United States, about 33 miles northwest of Dayton. It had a population of 51,881 at the 2020 census, an estimated 51,594 by 2024, and covers 600 square miles (1,600 km2) centred near 40°08′N 84°37′W.

Greenville is the county seat and the county’s largest city; its postal code is 45331. The county holds 1 city, 20 incorporated villages and roughly 28 unincorporated communities across 20 townships, and it runs on Eastern Time. Its FIPS code is 39037.

Towns & Villages in Darke County

Darke County has 21 incorporated places on record: 1 city and 20 villages, plus dozens of smaller unincorporated communities with no local government of their own. Village is Ohio’s official term for an incorporated place below city size; Unincorp. covers crossroads and rural hamlets with no formal boundary.

Two villages straddle county lines. Bradford’s 1,796 residents are split by Ohio State Route 721 (Miami Avenue), which also marks the county line; historically most of the village’s population has lived on the Miami County side, with the smaller Darke County portion sitting in Adams Township. Burkettsville sits astride Darke and Mercer counties as well, and its 272-resident total is not broken out by county.

ZIP Codes

• 45331 — Greenville
• 45303 — Ansonia
• 45304 — Arcanum (also serves Castine, Gordon and Ithaca)
• 45308 — Bradford (shared with the Miami County side)
• 45310 — Burkettsville (shared with the Mercer County side)
• 45328 — Gettysburg
• 45332 — Hollansburg
• 45346 — New Madison
• 45348 — New Weston (also serves Rossburg)
• 45350 — North Star
• 45351 — Osgood
• 45352 — Palestine
• 45358 — Pitsburg
• 45380 — Versailles
• 45388 — Yorkshire
• 45390 — Union City

Wayne Lakes has no ZIP code of its own; published sources do not identify which neighboring post office serves it.

Townships

Geography

Darke County lies on a flat to gently rolling glacial till plain in west-central Ohio. Of its 600 square miles, 598 are land and 1.7 are water, about 0.3 percent — low for the region, since the county has no large natural lake. Greenville Creek, which powers the historic Bear’s Mill on the county’s east side, runs through the county seat. The Mississinewa River has its headwaters in northwestern Darke County, within two miles of the start of the Wabash, and flows west into Indiana to join the Wabash River near Peru.

Mercer County lies to the north, Shelby and Miami counties to the east, Montgomery County to the southeast, Preble County to the south, Wayne County, Indiana to the southwest, and Randolph and Jay counties, Indiana to the west. Mercer County, Shelby County, Miami County, Montgomery County, Preble County, Wayne County, Indiana, Randolph County, Indiana and Jay County, Indiana all border Darke directly.

Demographics

Darke County had a population of 51,881 at the 2020 census, and the latest estimate puts the county near 51,594 residents in 2024, a slight decline. Greenville and Versailles are the two largest communities, with Greenville alone holding almost a quarter of the county’s population. Median household income runs $64,486, below Ohio’s statewide figure of $67,769. Population density works out to roughly 87 people per square mile of land, low for Ohio and typical of a farm county well outside the Dayton metro core.

Economy & Local Life

Manufacturing employs the most county residents, about 6,039 workers, followed by health care and social assistance at 3,173 and retail trade at 2,603. KitchenAid and BASF North America both keep offices in Greenville, and the Garst Museum there holds one of the country’s largest collections of Annie Oakley memorabilia, tied to her birth near the county. Eldora Speedway, a half-mile dirt oval in Allen Township near New Weston, hosts national dirt-track racing, including the World 100 each September, first run in 1971 and still its best-attended event of the year, and the Kings Royal sprint-car race each July.

History

Ohio’s General Assembly created Darke County on 3 January 1809, and it was organized in 1817. It was named for William Darke, an officer in the American Revolutionary War. The Treaty of Greenville, signed 3 August 1795 at Fort Greene Ville on the site of the future county seat, ended the Northwest Indian War and ceded most of southern and eastern Ohio to the United States.

General Arthur St. Clair’s army, retreating after its defeat by a Native American confederation in November 1791, fell back to Fort Jefferson, an outpost in what is now Neave Township. Bear’s Mill, on Greenville Creek between Greenville and Gettysburg, was built in 1849 by contractor Manning Hart and completed by Gabriel Bear; it still operates today as a working gristmill and milling museum. The railroad reached the county around 1850, turning Greenville into a regional trade hub.

Getting There

No interstate highway crosses Darke County. US Route 127 runs north–south and US Route 36 runs east–west, crossing at Greenville; State Routes 121, 49, 47, 571, 118, 726, 503, 722 and 185 fill in the rest of the network.

• Dayton — about 33 miles southeast
• Sidney — about 27 miles northeast
• Piqua — about 20 miles east
• Richmond, Indiana — about 25 miles southwest

James M. Cox Dayton International Airport, about 35 miles southeast of Greenville, is the nearest major commercial airport. Darke County Airport, a general-aviation field seven miles from Greenville in Versailles, handles local air traffic. Darke County has no passenger rail; the nearest Amtrak station is in Connersville, Indiana, about 45 miles southwest on the Cardinal line.

Frequently Asked Questions

Where is Darke County located?
It sits in west-central Ohio on the Indiana border, about 33 miles northwest of Dayton, bordered by Mercer, Shelby, Miami, Montgomery and Preble counties in Ohio and Wayne, Randolph and Jay counties in Indiana.

What is the population of Darke County?
51,881 at the 2020 census, with a 2024 estimate near 51,594.

How big is Darke County?
600 square miles (1,600 km2), of which 598 square miles are land.

What is the county seat of Darke County?
Greenville, site of the 1795 Treaty of Greenville, is the county seat and largest city.

How many towns and villages are in Darke County?
One city, Greenville, and 20 incorporated villages — including Versailles, Arcanum, Bradford and Union City — plus dozens of unincorporated hamlets.

What ZIP codes does Darke County use?
45331 for Greenville, 45380 for Versailles, 45304 for Arcanum, Castine, Gordon and Ithaca, and separate codes for each of the county’s other villages.

What is Darke County known for?
Eldora Speedway’s dirt-track racing, the Garst Museum’s Annie Oakley collection, and Bear’s Mill, an 1849 gristmill still grinding grain on Greenville Creek.

More counties in this state: Towns and villages in Ohio.