The county's distance from the large metro areas of San Francisco and Los Angeles has helped it to retain its rural character and reminders of old California abound. Commonly referred to as "the Central Coast," the area is more rural and agricultural than many other coastal regions in California. Father Junipero Serra founded the Mission San Luis Obispo de Tolosa in 1772 and the Mission is today an active part of downtown San Luis Obispo (popularly referred to as SLO or SLO-town). The small size of the county's communities, scattered along the beaches, coastal hills, and mountains of the Santa Lucia range, provides a wide variety of coastal and inland hill ecologies to support many kinds of fishing, agriculture, and tourist activities.
The mainstays of the economy are California Polytechnic State University with its almost 20,000 students, tourism, and agriculture. San Luis Obispo County is the third largest producer of wine in California, surpassed only by Sonoma and Napa Counties. Wine grapes are by far the largest agricultural crop in the county, and the wine production they support creates a direct economic impact and a growing wine country vacation industry.
The town of San Simeon is located at the foot of the hill where newspaper publisher William Randolph Hearst built the famed Hearst Castle. Other coastal towns include Cambria, Morro Bay and Cayucos to the north of San Luis Obispo city, and Avila Beach and the Five Cities to the south: Arroyo Grande, Grover Beach, Oceano, Pismo Beach and Shell Beach. Nipomo, just south of the Five Cities, borders northern Santa Barbara County. Inland, the cities of Paso Robles, Templeton, and Atascadero lie along the Salinas River, near the Paso Robles wine region. Just south of Cambria lies Harmony, the smallest town in California with a population of 18.
As of the census of 2000, there were 246,681 residents, 92,739 households, and 58,611 families in the county. The population density was 75 people per square mile (29/km²). There were 102,275 housing units at an average density of 31 per square mile (12/km²). The racial makeup of the county was 84.60% White, 2.03% Black or African American, 0.95% Native American, 2.66% Asian, 0.12% Pacific Islander, 6.21% from other races, and 3.44% from two or more races. 16.29% of the population were Hispanic or Latino of any race. 13.9% were of German, 11.4% English, 9.7% Irish, 6.1% American and 5.7% Italian ancestry according to Census 2000. 85.7% spoke English and 10.7% Spanish as their first language.
There were 92,739 households out of which 28.2% had children under the age of 18 living with them, 50.40% were married couples living together, 9.1% had a female householder with no husband present, and 36.8% were non-families. 26.0% of all households were made up of individuals and 10.3% had someone living alone who was 65 years of age or older. The average household size was 2.49 and the average family size was 3.01.
In the county the population was spread out with 21.7% under the age of 18, 13.60% from 18 to 24, 27.0% from 25 to 44, 23.3% from 45 to 64, and 14.5% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 105.6 males. For every 100 females age 18 and over, there were 105.2 males.
The median income for a household in the county was $42,428, and the median income for a family was $52,447. Males had a median income of $40,726 versus $27,450 for females. The per capita income for the county was $21,864. About 6.8% of families and 12.8% of the population were below the poverty line, including 11.4% of those under age 18 and 5.9% of those age 65 or over.
San Luis Obispo County is served by Amtrak trains and Greyhound Lines buses. The San Luis Obispo Regional Transit Authority provides countywide service along US 101 as well as service to Morro Bay, Los Osos, Cambria and San Simeon.
The cities of San Luis Obispo, Atascadero and Paso Robles operate their own local bus services; all of these connect with SLORTA routes.
Intercity service is provided by Amtrak trains, Greyhound and Orange Belt Stages buses.