As of the census of 2000, there were 14,985 people, 4,726 households, and 3,501 families residing in the county. The population density was 17 people per square mile (6/km²). There were 5,500 housing units at an average density of 6 per square mile (2/km²). The racial makeup of the county was 72.47% White, 8.66% Black or African American, 0.30% Native American, 0.25% Asian, 16.56% from other races, and 1.77% from two or more races. 48.19% of the population were Hispanic or Latino of any race.
There were 4,726 households out of which 35.10% had children under the age of 18 living with them, 59.40% were married couples living together, 11.00% had a female householder with no husband present, and 25.90% were non-families. 23.90% of all households were made up of individuals and 13.30% had someone living alone who was 65 years of age or older. The average household size was 2.69 and the average family size was 3.20.
In the county, the population was spread out with 25.60% under the age of 18, 8.90% from 18 to 24, 30.70% from 25 to 44, 20.50% from 45 to 64, and 14.30% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 124.30 males. For every 100 females age 18 and over, there were 129.90 males.
The median income for a household in the county was $28,211, and the median income for a family was $32,745. Males had a median income of $27,259 versus $16,739 for females. The per capita income for the county was $15,011. About 16.40% of families and 19.70% of the population were below the poverty line, including 29.20% of those under age 18 and 12.80% of those age 65 or over.