When Grand County was created February 2, 1874 it was carved out of Summit County and contained land to the western and northern borders of the state, which is in present-day Moffat County and Routt County. It was named after Grand Lake and the Grand River, an old name for the upper Colorado River, which has its headwaters in the county. On January 29, 1877 Routt County was created and Grand County shrunk down to its current western boundary. When valuable minerals were found in North Park, Grand County claimed the area as part of its county, a claim Larimer County also held. It took a decision by the Colorado Supreme Court in 1886 to declare North Park part of Larimer County, setting Grand County's northern boundary.
Geography
According to the U.S. Census Bureau, the county has a total area of, of which is land and is water.
At the 2000 census there were 12,442 people in 5,075 households, including 3,217 families, in the county. The population density was 7 people per square mile. There were 10,894 housing units at an average density of 6 per square mile. The racial makeup of the county was 95.15% White, 0.48% Black or African American, 0.43% Native American, 0.68% Asian, 0.10% Pacific Islander, 2.00% from other races, and 1.15% from two or more races. 4.36% of the population were Hispanic or Latino of any race. 23.8% were of German, 12.6% Irish, 10.0% English and 7.3% American ancestry. Of the 5,075 households 28.10% had children under the age of 18 living with them, 54.70% were married couplesliving together, 5.20% had a female householder with no husband present, and 36.60% were non-families. 24.80% of households were one person and 4.80% were one person aged 65 or older. The average household size was 2.37 and the average family size was 2.85. The age distribution was 21.80% under the age of 18, 9.00% from 18 to 24, 34.70% from 25 to 44, 26.80% from 45 to 64, and 7.80% 65 or older. The median age was 37 years. For every 100 females there were 112.70 males. For every 100 females age 18 and over, there were 115.70 males. The median household income was $47,759 and the median family income was $55,217. Males had a median income of $34,861 versus $26,445 for females. The per capita income for the county was $25,198. About 5.40% of families and 7.30% of the population were below the poverty line, including 7.90% of those under age 18 and 6.10% of those age 65 or over.
