As of the census² of 2000, there were 179,727 people, 61,364 households, and 45,225 families residing in the county. The population density was 34 people per square mile (13/km²). There were 81,154 housing units at an average density of 15/sq mi (6/km²). The racial makeup of the county was 70.42% White, 2.76% Black or African American, 7.81% Native American, 0.60% Asian, 0.08% Pacific Islander, 15.66% from other races, and 2.67% from two or more races. 29.86% of the population were Hispanic or Latino of any race. 21.86% reported speaking Spanish at home, while 1.44% speak O'odham and 0.02% speak Apache [1].
There were 61,364 households out of which 29.80% had children under the age of 18 living with them, 56.90% were married couples living together, 11.50% had a female householder with no husband present, and 26.30% were non-families. 21.10% of all households were made up of individuals and 9.20% had someone living alone who was 65 years of age or older. The average household size was 2.68 and the average family size was 3.09.
In the county the population was spread out with 25.10% under the age of 18, 8.70% from 18 to 24, 27.30% from 25 to 44, 22.70% from 45 to 64, and 16.20% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 114.20 males. For every 100 females age 18 and over, there were 117.00 males.
The median income for a household in the county was $35,856, and the median income for a family was $39,548. Males had a median income of $31,544 versus $23,726 for females. The per capita income for the county was $16,025. About 12.10% of families and 16.90% of the population were below the poverty line, including 25.50% of those under age 18 and 8.70% of those age 65 or over.