As of the census of 2000, there were 82,874 people, 31,769 households, and 22,683 families residing in the county. The population density was 159 people per square mile (61/km²). There were 33,796 housing units at an average density of 65 per square mile (25/km²). The racial makeup of the county was 95.50% White, 1.05% Black or African American, 0.40% Native American, 1.49% Asian, 0.03% Pacific Islander, 0.44% from other races, and 1.09% from two or more races. 1.55% of the population were Hispanic or Latino of any race. 28.6% were of German, 11.5% English, 10.2% United States or American, 8.9% Irish and 6.1% Polish ancestry according to Census 2000. 96.7% spoke English and 1.6% Spanish as their first language. The county is said to be mostly of Republican influence, an abnormality from its neighboring counties, Saginaw and Bay who mainly vote Democrat.
There were 31,769 households out of which 34.90% had children under the age of 18 living with them, 60.10% were married couples living together, 8.10% had a female householder with no husband present, and 28.60% were non-families. 23.50% of all households were made up of individuals and 9.00% had someone living alone who was 65 years of age or older. The average household size was 2.56 and the average family size was 3.04.
In the county the population was spread out with 26.90% under the age of 18, 8.70% from 18 to 24, 29.20% from 25 to 44, 23.20% from 45 to 64, and 12.00% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 96.30 males. For every 100 females age 18 and over, there were 93.30 males.
The median income for a household in the county was $45,674, and the median income for a family was $55,483. Males had a median income of $45,656 versus $27,470 for females. The per capita income for the county was $23,383. About 5.70% of families and 8.40% of the population were below the poverty line, including 9.50% of those under age 18 and 7.50% of those age 65 or over.