Teller County is one of the 64 counties in the U.S. state of Colorado. As of the 2010 census, the population was 23,350. The county seat is Cripple Creek, and the most populous city is Woodland Park.
According to the U.S. Census Bureau, the county has a total area of 559 square miles (1,450 km), of which 557 square miles (1,440 km) is land and 1.9 square miles (4.9 km) (0.3%) is water.
As of the census of 2000, there were 20,555 people, 7,993 households, and 5,922 families residing in the county. The population density was 37 people per square mile (14/km²). There were 10,362 housing units at an average density of 19 per square mile (7/km²). The racial makeup of the county was 94.92% White, 0.55% Black or African American, 0.97% Native American, 0.58% Asian, 0.08% Pacific Islander, 0.90% from other races, and 2.00% from two or more races. 3.49% of the population were Hispanic or Latino of any race.
There were 7,993 households out of which 33.60% had children under the age of 18 living with them, 64.20% were married couples living together, 6.60% had a female householder with no husband present, and 25.90% were non-families. 19.60% of all households were made up of individuals and 4.00% 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 2.94.
In the county, the population was spread out with 25.90% under the age of 18, 5.60% from 18 to 24, 31.20% from 25 to 44, 29.80% from 45 to 64, and 7.50% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 102.70 males. For every 100 females age 18 and over, there were 100.90 males.
The median income for a household in the county was $50,165, and the median income for a family was $57,071. Males had a median income of $37,194 versus $26,934 for females. The per capita income for the county was $23,412. About 3.40% of families and 5.40% of the population were below the poverty line, including 6.90% of those under age 18 and 4.20% of those age 65 or over.