Adjacent counties

• Clark County - north
• Wood County - east
• Juneau County - southeast
• Monroe County - south
• La Crosse County - southwest
• Trempealeau County - west
• Eau Claire County - northwest

Major highways

Railroads

• Canadian National
• Union Pacific

Buses

• Black River Falls Public Transit
• List of intercity bus stops in Wisconsin

2020 census

As of the census of 2020,^[1] the population was 21,145. The population density was 21.4 people per square mile (8.3 people/km²). There were 9,613 housing units at an average density of 9.7 units per square mile (3.7 units/km²). The racial makeup of the county was 85.8% White, 6.5% Native American, 2.1% Black or African American, 0.4% Asian, 1.2% from other races, and 4.1% from two or more races. Ethnically, the population was 3.2% Hispanic or Latino of any race.

2000 census

As of the census^[10] of 2000, there were 19,100 people, 7,070 households, and 4,835 families residing in the county. The population density was 19 people per square mile (7.3 people/km²). There were 8,029 housing units at an average density of 8 units per square mile (3.1 units/km²). The racial makeup of the county was 89.58% White, 2.27% Black or African American, 6.16% Native American, 0.16% Asian, 0.04% Pacific Islander, 1.01% from other races, and 0.79% from two or more races. 1.87% of the population were Hispanic or Latino of any race. 31.4% were of German, 30.2% Norwegian and 5.2% Irish ancestry. 94.7% spoke English, 2.2% Spanish and 1.5% Winnebago as their first language.

There were 7,070 households, out of which 31.00% had children under the age of 18 living with them, 55.40% were married couples living together, 8.60% had a female householder with no husband present, and 31.60% were non-families. 26.20% of all households were made up of individuals, and 11.80% had someone living alone who was 65 years of age or older. The average household size was 2.49 and the average family size was 3.00.

In the county, the population was spread out, with 24.10% under the age of 18, 8.80% from 18 to 24, 29.40% from 25 to 44, 22.80% from 45 to 64, and 14.90% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 114.60 males. For every 100 females age 18 and over, there were 116.30 males.

In 2017, there were 227 births, giving a general fertility rate of 74.0 births per 1000 women aged 15–44, the 10th highest rate out of all 72 Wisconsin counties. Of these, 14 of the births occurred at home.^[11] Additionally, there were 7 reported induced abortions performed on women of Jackson County residence in 2017.^[12]

City

• Black River Falls (county seat)

Villages

• Alma Center
• Hixton
• Melrose
• Merrillan
• Taylor

Towns

Census-designated places

• Hatfield
• Millston
• Mission
• Sand Pillow

Other unincorporated communities

Ghost towns/neighborhoods

• Charter Oak Mills
• Clay
• Rogneys
• Wrightsville