Traill County is a county in North Dakota, United States, in the eastern part of the state along the Minnesota border. It had a population of 7,997 at the 2020 census and covers 862 square miles (2,234 km2) centred near 47°26′47″N 97°09′53″W.
Hillsboro is the county seat, and its postal code is 58045. The county has 9 incorporated cities and 11 unincorporated communities. Traill County sits in the Central time zone.
Towns & Villages in Traill County
Twenty places are recognized across Traill County: 9 incorporated cities (in North Dakota, every incorporated place carries the legal designation “city” regardless of size) and 11 unincorporated communities. Grandin and Reynolds each straddle the county line, with part of their built-up area lying in neighboring Cass and Steele counties.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Hillsboro | City · seat | — | 58045 |
| Mayville | City | — | 58257 |
| Hatton | City | — | 58240 |
| Portland | City | — | 58274 |
| Buxton | City | — | 58218 |
| Galesburg | City | — | 58035 |
| Clifford | City | — | 58016 |
| Grandin | City (part) | — | — |
| Reynolds | City (part) | — | — |
| Caledonia | Unincorp. | — | 58219 |
| Cummings | Unincorp. | — | 58223 |
| Blanchard | Unincorp. | — | 58009 |
| Alton | Unincorp. | — | — |
| Greenfield | Unincorp. | — | — |
| Kelso | Unincorp. | — | — |
| Murray | Unincorp. | — | — |
| Portland Junction | Unincorp. | — | — |
| Preston | Unincorp. | — | — |
| Roseville | Unincorp. | — | — |
| Taft | Unincorp. | — | — |
ZIP Codes
- 58045 — Hillsboro (county seat)
- 58257 — Mayville
- 58240 — Hatton
- 58274 — Portland
- 58218 — Buxton
- 58035 — Galesburg
- 58016 — Clifford
- 58219 — Caledonia
- 58223 — Cummings
- 58009 — Blanchard
Ten ZIP codes cover Traill County. Grandin, Reynolds, and the county’s small unincorporated communities are served by the nearest post-office town rather than a ZIP code of their own.
Geography
Traill County lies in the Red River Valley, a flat glacial-lake plain that runs the length of North Dakota’s eastern edge. The land is almost entirely farmland — open, gently rolling fields with few natural rises — drained toward the Red River of the North, which forms the county’s eastern boundary with Minnesota. The Goose River crosses the county from west to east, passing near Hillsboro and Mayville on its way to join the Red River. Of the county’s total area, 861.9 square miles are land and just 0.6 square miles are water.
Traill County borders Grand Forks County to the north, Polk County, Minnesota, to the northeast across the Red River, Norman County, Minnesota, to the east, Cass County to the south, and Steele County to the west.
Demographics
Traill County had 7,997 residents at the 2020 census, spread across a population density of roughly 9 people per square mile. Hillsboro and Mayville are the two largest communities, with the balance of the population in the county’s smaller cities and its farm townships. Median household income in Traill County runs close to the North Dakota median of $76,525, reflecting the county’s stable agricultural economy and modest cost of living.
Economy & Local Life
Agriculture drives Traill County’s economy. Spring wheat, soybeans, corn, sugar beets, and dry edible beans are the leading crops on the county’s flat, fertile Red River Valley soil, and grain elevators anchor most of its small towns. Mayville is home to Mayville State University, a public university that gives the city a year-round student population and is the county’s largest single employer outside agribusiness. Hillsboro, the county seat, hosts the county courthouse — a 1905 building listed on the National Register of Historic Places — along with the county’s main administrative and retail activity.
History
Traill County was created by the Dakota Territorial Legislature on January 12, 1875, and organized on February 23, 1875. It was named for Walter John Strickland Traill, an official of the Hudson’s Bay Company and son of the Canadian pioneer writer Catharine Parr Traill. Settlement followed the arrival of the railroad through the Red River Valley in the late 1870s and 1880s, which platted most of the county’s present-day towns as grain-shipping points along the line. The Traill County Courthouse in Hillsboro, completed in 1905, remains the county’s civic landmark.
Getting There
Interstate 29 runs north–south along the county’s eastern side, with US Route 81 providing a parallel route through the middle of the county. North Dakota Highways 18 and 200 cross the county east–west, linking its towns to the interstate.
- Fargo — 45 miles south
- Grand Forks — 35 miles north
- Grafton — 45 miles north
- Casselton — 40 miles southwest
Hillsboro Municipal Airport and Mayville Municipal Airport serve general aviation locally; the nearest commercial airport is Hector International Airport in Fargo.
Frequently Asked Questions
Where is Traill County?
It is in eastern North Dakota, in the Red River Valley along the Minnesota border, between Grand Forks and Fargo.
What is the population of Traill County?
7,997 people at the 2020 census.
How big is Traill County?
862 square miles (2,234 km2), of which 861.9 square miles are land.
What is the Traill County seat?
Hillsboro is the county seat; Mayville is the county’s largest city.
How many towns are in Traill County?
Nine incorporated cities and eleven unincorporated communities.
What ZIP codes are in Traill County?
Ten ZIP codes, led by 58045 (Hillsboro) and 58257 (Mayville).
Why is it called Traill County?
It is named for Walter John Strickland Traill, a Hudson’s Bay Company official, when the county was organized in 1875.
More counties in this state: Towns and villages in North Dakota.