Montgomery County was formed on 9 December 1842 and was named in honor of Richard Montgomery, an American Revolutionary War general killed in 1775 while attempting to capture Quebec City, Quebec, Canada.
According to the U.S. Census Bureau, the county has a total area of 2,073 km² (800 mi²). 2,023 km² (781 mi²) of it is land and 50 km² (19 mi²) of it is water. The total area is 2.42% water.
As of the census2 of 2000, there are 9,245 people, 3,785 households, and 2,747 families residing in the county. The population density is 5/km² (12/mi²). There are 5,048 housing units at an average density of 2/km² (6/mi²). The racial makeup of the county is 95.42% White, 0.29% Black or African American, 1.11% Native American, 0.37% Asian, 0.01% Pacific Islander, 1.56% from other races, and 1.23% from two or more races. 2.53% of the population are Hispanic or Latino of any race.
There are 3,785 households out of which 28.00% have children under the age of 18 living with them, 62.60% are married couples living together, 7.00% have a female householder with no husband present, and 27.40% are non-families. 24.50% of all households are made up of individuals and 12.20% have someone living alone who is 65 years of age or older. The average household size is 2.41 and the average family size is 2.85.
In the county the population is spread out with 23.50% under the age of 18, 6.20% from 18 to 24, 25.00% from 25 to 44, 26.30% from 45 to 64, and 18.90% who are 65 years of age or older. The median age is 42 years. For every 100 females there are 96.20 males. For every 100 females age 18 and over, there are 95.00 males.
The median income for a household in the county is $28,421, and the median income for a family is $32,769. Males have a median income of $25,865 versus $18,063 for females. The per capita income for the county is $14,668. 17.00% of the population and 13.00% of families are below the poverty line. Out of the total people living in poverty, 22.50% are under the age of 18 and 16.00% are 65 or older.