The Dakota Territory legislature enacted a January 8, 1873 law to create a county named Mercer, whose boundaries would be identical to Pratt (a now-extinct county). This county did not come into existence, as the 1873 act was nullified on January 14, 1875, by the legislature. On that date the legislature created another Mercer County, from previously unorganized territory. The county was named for William Henry Harrison Mercer,[3] (1844–1901), a rancher who settled north of Bismarck in 1869. The unorganized county was not attached to another county for judicial or administrative purposes; this condition continued until November 6, 1883, when the county government was organized.
The county boundaries were altered in 1879, 1881, 1885, 1892, and 1901. Its boundaries have remained unchanged since 1901.[4][5]
Outline map of Mercer County, North Dakota, 1918
Geography
The northern boundary of Mercer County is delineated by Lake Sakakawea, created in 1956 on the Missouri River. The county's eastern boundary is delineated by the river as it flows southeastward from the dam that created the lake. The county terrain consists of rolling hills, largely devoted to agriculture.[6] The terrain slopes to the north and east; its highest point is near the midpoint of its southern boundary, at 2,451 ft (747 m) ASL.[7] The county has a total area of 1,112 square miles (2,880 km2), of which 1,043 square miles (2,700 km2) is land and 70 square miles (180 km2) (6.3%) is water.[8]
The southwestern corner counties of North Dakota (Adams, Billings, Bowman, Golden Valley, Grant, Hettinger, Slope, Stark) observe Mountain Time. The counties of McKenzie, Dunn, and Sioux counties are split, with their northern portions observing Central Time and the southern portions observing Mountain Time.
Prior to [9] November 7, 2010, the western portion of Mercer County was in Mountain Time. But it was all moved into the Central Time on that date.
U.S. Decennial Census[11] 1790-1960[12] 1900-1990[13] 1990-2000[14] 2010-2020[1]
2020 census
As of the census of 2020, there were 8,350 people.
2010 census
As of the census of 2010, there were 8,424 people, 3,625 households, and 2,500 families in the county. The population density was 8.08 people per square mile (3.12 people/km2). There were 4,450 housing units at an average density of 4.27 units per square mile (1.65/km2). The racial makeup of the county was 95.6% white, 2.3% American Indian, 0.3% Asian, 0.2% black or African American, 0.1% Pacific islander, 0.4% from other races, and 1.1% from two or more races. Those of Hispanic or Latino origin made up 1.4% of the population. In terms of ancestry, 64.7% were German, 21.5% were Norwegian, 6.6% were Russian, 6.2% were Irish, and 2.2% were American.
Of the 3,625 households, 26.5% had children under the age of 18 living with them, 60.1% were married couples living together, 5.0% had a female householder with no husband present, 31.0% were non-families, and 27.3% of all households were made up of individuals. The average household size was 2.29 and the average family size was 2.76. The median age was 46.3 years.
The median income for a household in the county was $60,191 and the median income for a family was $71,075. Males had a median income of $63,321 versus $32,294 for females. The per capita income for the county was $30,616. About 4.1% of families and 6.2% of the population were below the poverty line, including 7.2% of those under age 18 and 11.2% of those age 65 or over.
Mercer County voters have traditionally voted Republican. In no national election since 1936 has the county selected the Democratic Party candidate (as of 2024).
United States presidential election results for Mercer County, North Dakota[15]
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