As of the 2000 census, there were 31,002 people, 12,146 households, and 8,514 families living in the county. The population density was 8 people per square mile. There were 14,066 housing units at an average density of 4 per square mile. The racial makeup of the county was 75.67% White, 0.52% Black or African American, 1.35% Native American, 0.29% Asian, 0.03% Pacific Islander, 19.02% from other races, and 3.11% from two or more races. 48.79% of the population were Hispanic or Latino of any race. There were 12,146 households out of which 31.30% had children under the age of 18 living with them, 52.70% were married couplesliving together, 12.90% had a female householder with no husband present, and 29.90% were non-families. 25.70% of all households were made up of individuals and 10.70% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 3.01. In the county, the population was spread out with 26.20% under the age of 18, 8.50% from 18 to 24, 23.70% from 25 to 44, 25.10% from 45 to 64, and 16.50% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 95.10 males. For every 100 females age 18 and over, there were 91.30 males. The median income for a household in the county was $29,134, and the median income for a family was $34,231. Males had a median income of $31,126 versus $19,627 for females. The per capita income for the county was $14,597. About 15.10% of families and 18.70% of the population were below the poverty line, including 25.90% of those under age 18 and 9.50% of those age 65 or over.
2010 census
As of the 2010 census, there were 29,514 people, 12,586 households, and 7,941 families living in the county. The population density was. There were 14,693 housing units at an average density of. The racial makeup of the county was 84.9% white, 1.4% American Indian, 0.9% black or African American, 0.4% Asian, 0.1% Pacific islander, 9.6% from other races, and 2.8% from two or more races. Those of Hispanic or Latino origin made up 48.3% of the population. In terms of ancestry, 11.9% were English, 11.8% were German, 10.4% were Irish, and 2.9% were American. Of the 12,586 households, 26.9% had children under the age of 18 living with them, 45.3% were married couples living together, 12.6% had a female householder with no husband present, 36.9% were non-families, and 30.9% of all households were made up of individuals. The average household size was 2.30 and the average family size was 2.86. The median age was 45.9 years. The median income for a household in the county was $36,591 and the median income for a family was $44,360. Males had a median income of $38,731 versus $27,161 for females. The per capita income for the county was $21,164. About 11.7% of families and 14.8% of the population were below the poverty line, including 23.8% of those under age 18 and 5.2% of those age 65 or over.
