Williams County is located on the western border of the U.S. state of North Dakota, next to Montana. As of the 2020 census, the population was 40,950. making it the fifth most populous county in North Dakota. Its county seat is Williston. The Williston Micropolitan Statistical Area includes all of Williams County. It is bordered on the south by the upper Missouri River, whose confluence with its tributary Yellowstone River is located just east of the border with Montana.

History

There have been two Williams counties in the history of North Dakota. The first, created in 1873, was located south of the Missouri River near where Dunn and Mercer counties are today. This county continued to exist through North Dakota statehood, and while the second Williams County was created in 1891. The first Williams County was extinguished by a county referendum on November 8, 1892; part of its territory was absorbed by Mercer County and the rest reverted to an unorganized territory. The second Williams County was created by the North Dakota legislature on March 2, 1891, from the previous counties of Buford and Flannery, which were dissolved. The government of this county was organized on December 8, 1891. This county's boundaries were altered in 1910, when a portion of its territory was annexed to create Divide County. Its boundaries have remained unchanged since then. The county is named for Erastus Appleman Williams, a European-American settler who served in the Dakota Territory legislature and the North Dakota legislature. In June 2014, lightning struck a Williams County Oasis Petroleum saltwater disposal facility. It sparked a fire that destroyed the facility, burning 630 gallons of oil and tens of thousands of gallons of brine.

Geography

Williams County lies on the west edge of North Dakota. Its west boundary line abuts the east boundary line of the state of Montana. The Missouri River flows eastward along the county's south boundary line from the confluence with its tributary Yellowstone River, located on the Dakota side of the state border with Montana. Horse Creek and Willow Creek flow to the west across the upper portion of the county. The terrain consists of isolated hills amid rolling, hilly, semi-arid stretches. The area is partly devoted to agriculture. The terrain is highest across its midpoint, and slopes to the NW and SE. Its highest point is a hill near the NE corner, at 2,470 ft ASL. The county has a total area of 2148 sqmi, of which 2077 sqmi is land and 70 sqmi (3.3%) is water. It is the fourth-largest county in North Dakota by area. Lake Sakakawea, a reservoir on the Missouri River, is situated on the southern boundary of the county. Little Muddy Creek is entirely within Williams County. The confluence of the Yellowstone River with the Missouri is west of Williston. The Fort Union Trading Post National Historic Site is located in Williams County along the Missouri River on the Montana border. Williams County is one of several western North Dakota counties with significant exposure to the Bakken formation in the Williston Basin.

Major highways

Transit

Adjacent counties

Protected areas

Lakes

Demographics

2020 census

As of the 2020 census, there were 40,950 people, 16,095 households, and 9,585 families in the county. The population density was 19.7 PD/sqmi There were 20,227 housing units.

2010 census

As of the 2010 census, there were 22,398 people, 9,293 households, and 5,746 families in the county. The population density was 10.8 PD/sqmi. There were 10,464 housing units at an average density of 5.0 /sqmi. The racial makeup of the county was 92.1% white, 4.0% American Indian, 0.4% Asian, 0.3% black or African American, 0.3% from other races, and 2.9% from two or more races. Those of Hispanic or Latino origin made up 1.9% of the population. In terms of ancestry, 46.2% were of Norwegian, 35.9% of German, 9.8% of Irish, 4.5% of Swedish and 4.4% of English ancestry. Of the 9,293 households, 28.5% had children under the age of 18 living with them, 49.8% were married couples living together, 7.7% had a female householder with no husband present, 38.2% were non-families, and 31.5% of all households were made up of individuals. The average household size was 2.35 and the average family size was 2.95. The median age was 39.0 years. The median income for a household in the county was $55,396 and the median income for a family was $67,875. Males had a median income of $50,735 versus $27,071 for females. The per capita income for the county was $29,153. About 4.7% of families and 8.7% of the population were below the poverty line, including 9.7% of those under age 18 and 10.4% of those age 65 or over.

Population by decade

Media

Communities

Cities

Census-designated places

Other unincorporated communities

Townships

Defunct townships

Politics

Williams County voters have been reliably Republican for decades. In no national election since 1964 has the county selected the Democratic Party candidate.

Education

School districts include: Former districts include: