Its location sits halfway between the cities of San Francisco and Los Angeles on the north–south axis of U.S. Route 101 and Pacific Coast Highway (PCH).

[5] TTB was created in January 2003, when the Bureau of Alcohol, Tobacco and Firearms, or ATF, was extensively reorganized under the provisions of the Homeland Security Act of 2002.

Despite conflicting accounts, the first recorded planting of a vineyard was probably by the Spanish Jesuit Missionary Eusebio Francisco Kino at Misión San Bruno in Baja California in 1683 implanting the first variety named "Misionéro."

In 1779, Franciscan missionaries under the direction of the Spanish Father Junípero Serra planted California's first vineyard at Mission San Juan Capistrano.

Father Serra sent an expedition down south from the capital of Alta California, Monterey, to build the San Luis Obispo mission.

The San Gabriel Mission, built from 1791 to 1805 using brick, mortar, and cut stone, is the oldest structure of its kind south of Monterey.

His legend is one of adventure, service to his country, viticulture, and travels abroad, from his village in southwestern France to Tahiti to Hangtown and finally to San Luis Obispo.

[33] San Luis Obispo county is hemmed-in close to the Pacific coastline by the Santa Lucia Range while over the hills lies the southern end of the Central Valley, which connects this area with northern California.

At the county's northern border, its largest viticultural area, Paso Robles, encompasses 669,253 acres (1,046 sq mi) defined by rolling hills and valleys with an average elevation between 600 and 1,000 feet (183–305 m).

The area is protected from marine air intrusion and coastal fogs by the Santa Lucia Mountains on the west and south.

This is a marked contrast to the York Mountain and SLO Coast viticultural areas to the west and south where coastal fogs are common with cooler temperatures in the summer months.

[11][34] On November 10, 2014, TTB issued the final rule in the Federal Register establishing eleven distinct appellations within the existing Paso Robles viticultural area.

According to the SLO Coast petition, 97 percent of the area is at or below 1,800 feet (550 m) in elevation, which corresponds to the approximate limit of the influence of the maritime climate.

Fog occurs over 55 percent of all nights during the growing season within the southern region of San Luis Obispo county.

[38] The term "SLO" is an historical and commonly used reference for the county and town initials as well as a description of the region's relaxed culture.