Harper County is a county in Oklahoma, United States, on the state’s northern border with Kansas, in the Panhandle-adjacent region of the northwest. It had a population of 3,272 at the 2020 census and covers 1,041 square miles (2,700 km2), of which 1,039 square miles (2,690 km2) are land and 2.0 square miles (5.2 km2) are water, centred near 36°47′N 99°39′W.
Buffalo is the county seat, and its postal code is 73834. The county holds four incorporated towns, one census-designated place, and a handful of unincorporated communities; Oklahoma counties have no civil townships. Harper County keeps Central time and its northern edge runs along two Kansas counties.
Towns & Villages in Harper County
Harper County has four incorporated towns — Buffalo, Laverne, May, and Rosston — plus the census-designated place of Selman and several smaller unincorporated communities. In the table below, CDP means census-designated place and Unincorp. means an unincorporated community with no municipal government.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Buffalo | City · seat | 1,039 | 73834 |
| Laverne | Town | — | 73848 |
| May | Town | — | 73851 |
| Rosston | Town | — | 73855 |
| Selman | CDP | — | — |
| Dunlap | Unincorp. | — | — |
| Willard | Unincorp. | — | — |
| Doby Springs | Unincorp. | — | — |
Doby Springs, on the North Canadian side of the county, is a historic settlement that never incorporated and is sometimes described as a ghost town today.
ZIP Codes
- 73834 — Buffalo (also serves the surrounding county seat area)
- 73848 — Laverne
- 73851 — May
- 73855 — Rosston
Selman and the county’s unincorporated communities share ZIP codes with their nearest post-office town rather than carrying their own.
Geography
Harper County sits in Oklahoma’s northwestern High Plains, a mix of sandy river bottoms and rolling upland pasture. The Cimarron River crosses the southern part of the county and the Beaver River (the upper North Canadian) crosses the north, and both have shaped the sandy-hills terrain found along their valleys.
Harper County borders Comanche County, Kansas to the northeast, Woods County to the east, Woodward County to the southeast, Ellis County to the south, Beaver County to the west, and Clark County, Kansas to the northwest.
Demographics
Harper County had 3,272 residents at the 2020 census, spread across a large, sparsely populated area at roughly 3.1 people per square mile. Buffalo, the county seat, is the largest community; Laverne, in the county’s east, is the second-largest town. Oklahoma’s statewide median household income is the Oklahoma median of $62,138; Harper County’s own median has historically run below that figure, in line with other rural Panhandle-region counties.
Economy & Local Life
Wheat farming and cattle ranching anchor Harper County’s economy, alongside oil and natural gas production that has operated across northwestern Oklahoma for decades. Wheat harvest in June draws custom cutting crews through the county, and cattle sales remain a regular fixture of local commerce. Buffalo and Laverne each host their own public school district, and county government and agriculture-support businesses provide most of the remaining local employment. Buffalo’s small-town square still centers the county’s civic life, with the courthouse, the county fairgrounds, and local churches anchoring most community gatherings.
History
Harper County was organized in 1907, at Oklahoma statehood, from the northwest corner of Woodward County. The land had been part of the Cherokee Outlet, opened to settlement in the 1893 land run that brought the first homesteaders into what is now the county. The county takes its name from Oscar Green Harper, who served as clerk of the Oklahoma Constitutional Convention. Railroad service reached the county in 1912, helping establish Buffalo and Laverne as the area’s main shipping points for grain and livestock. The county’s population peaked decades ago and has declined gradually since, a pattern common across rural western Oklahoma as farms consolidated and mechanized.
Getting There
U.S. Highways 64, 183, 270, 283, and 412 cross Harper County, along with State Highways 3, 34, 46, and 149.
- Woodward — about 40 miles southeast
- Dodge City, Kansas — about 65 miles north
- Woodward, Oklahoma — nearest larger trade center
The nearest airports with commercial or charter service are in Woodward and in Dodge City, Kansas.
Frequently Asked Questions
Where is Harper County, Oklahoma?
It is in the northwestern part of the state, on the Kansas border, roughly midway between the Oklahoma Panhandle and Woodward.
What is the population of Harper County?
Harper County had 3,272 residents at the 2020 census, making it one of Oklahoma’s least populous counties.
How big is Harper County?
The county covers 1,041 square miles (2,700 km2), of which 1,039 square miles are land.
What is the county seat of Harper County?
Buffalo is the county seat.
How many towns are in Harper County?
The county has four incorporated towns — Buffalo, Laverne, May, and Rosston — plus the community of Selman and a few smaller unincorporated places.
What ZIP codes are in Harper County?
The main ZIP codes are 73834 (Buffalo), 73848 (Laverne), 73851 (May), and 73855 (Rosston).
When was Harper County established?
It was organized in 1907 from the northwest corner of Woodward County, at the time of Oklahoma statehood.
More counties in this state: Towns and villages in Oklahoma.