As of the census of 2000, there were 131,441 people, 45,018 households, and 33,943 families residing in the county. The population density was 223/square mile (86/square&nbps;km). There were 47,965 housing units at an average density of 81/square mile (31/square km). The racial makeup of the county was 83.10% White, 0.32% Black or African American, 0.85% Native American, 0.80% Asian, 0.13% Pacific Islander, 12.17% from other races, and 2.62% from two or more races. Hispanic or Latino of any race were 18.61% of the population. 15.9% were of German, 12.7% English, 10.3% American and 7.6% Irish ancestry according to Census 2000.
There were 45,018 households out of which 39.80% had children under the age of 18 living with them, 60.70% were married couples living together, 10.10% had a female householder with no husband present, and 24.60% were non-families. 19.80% of all households were made up of individuals and 8.40% had someone living alone who was 65 years of age or older. The average household size was 2.85 and the average family size was 3.28.
In the county the population was spread out with 30.90% under the age of 18, 10.70% from 18 to 24, 28.30% from 25 to 44, 19.10% from 45 to 64, and 11.00% who were 65 years of age or older. The median age was 30 years. For every 100 females there were 98.70 males. For every 100 females age 18 and over, there were 96.30 males.
The median income for a household in the county was $35,884, and the median income for a family was $40,377. Males had a median income of $29,418 versus $22,044 for females. The per capita income for the county was $15,155. About 8.70% of families and 12.00% of the population were below the poverty line, including 14.50% of those under age 18 and 10.70% of those age 65 or over.
According to Canyon County Development Services, during 2007 there were approximately 926 building permits issued in the county, 63 approved subdivisions in the County, and 3 rezones. 99 conditional use permits were issued.