According to the United States Census Bureau, the city has a total area of 96.6 km² (37.3 mi²). 96.0 km² (37.1 mi²) of it is land and 0.6 km² (0.2 mi²) of it is water. The total area is 0.64% water.
As of the census2 of 2000, there are 33,938 people, 15,098 households, and 8,968 families residing in the city. The population density is 353.5/km² (915.6/mi²). There are 17,144 housing units at an average density of 178.6/km² (462.5/mi²). The racial makeup of the city is 92.93% White, 0.50% Black or African American, 1.27% Native American, 0.83% Asian, 0.06% Pacific Islander, 2.77% from other races, and 1.63% from two or more races. 8.17% of the population are Hispanic or Latino of any race.
There are 15,098 households out of which 18.1% have children under the age of 18 living with them, 48.7% are married couples living together, 7.9% have a female householder with no husband present, and 40.6% are non-families. 32.1% of all households are made up of individuals and 15.2% have someone living alone who is 65 years of age or older. The average household size is 2.11 and the average family size is 2.62.
In the city the population is spread out with 15.9% under the age of 18, 11.2% from 18 to 24, 18.9% from 25 to 44, 27.3% from 45 to 64, and 26.8% who are 65 years of age or older. The median age is 48 years. For every 100 females there are 96.9 males. For every 100 females age 18 and over, there are 94.3 males.
The median income for a household in the city is $35,446, and the median income for a family is $46,481. Males have a median income of $31,834 versus $22,982 for females. The per capita income for the city is $22,565. 13.1% of the population and 7.4% of families are below the poverty line. Out of the total people living in poverty, 14.4% are under the age of 18 and 6.4% are 65 or older.