The town grew steadily through the Mexican period before a rapid expansion of San Luis Obispo following the American Conquest of California.

One of the earliest villages lies south of San Luis Obispo and reflects the landscape of the early Holocene when estuaries came farther inland.

The Chumash people used marine resources of the inlets and bays along the Central Coast and inhabited a network of villages, including sites at Los Osos and Morro Creek.

The party traveled north along San Luis Obispo Creek, turned west through Los Osos Valley, and reached Morro Bay on September 9.

Over twenty-five mule loads of dried bear meat and seed were sent north to relieve the missionaries, soldiers, and neophytes (baptized natives).

With soldiers, muleteers, and pack animals carrying mission supplies, Junípero Serra set out from Carmel to reach the Valley of the Bears.

When the Mexican War of Independence from Spain broke out in 1810, all California missions had to become virtually self-sufficient, receiving few funds or supplies from Spanish sources.

Beginning soon after Mexico won her independence from Spain in 1821, anti-Spanish feelings led to calls for expulsion of the Spanish Franciscans and secularization of the missions.

[16] Robberies and murders that left no witnesses were carried out on along the El Camino Real and elsewhere around San Luis Obispo for several years.

Finally a gang of eight men committed a robbery with three murders and a kidnapping at the Rancho San Juan Capistrano del Camote in May 1858, that uncharacteristically left two witnesses alive.

Residents quickly turned to other venues, leading to the breaking up of many of the ranchos and a major change in the economic climate of the town, which focused less on cattle ranching and more on dairies, agriculture, and mined goods from then onward.

Today, Mee Heng Low chop suey shop is all that remains of the culture, although a slightly Chinatown-themed commercial development has been planned.

A display of some of the unearthed relics from this period can be seen on the first floor of the Palm Street parking garage, which was built over the location where Chinatown once stood.

These mountains are the headwaters for San Luis Obispo Creek, whose watershed encompasses 84 square miles (220 km2) surrounding the city and flows to the Pacific Ocean at Avila Beach.

[22] Nights remain cool year round due to cold-current ocean air in summer and being in a valley subject to inversion, although seldom cold.

[29] In 2016, they announced the closure of the Diablo Canyon Nuclear Power Plant in 2025, which was expected to cost the local economy 1,500 jobs with an average salary of $157,000, as well as nearly $1 billion annually in economic activity.

Four members of the Fire Department are also on the San Luis Obispo SWAT Team as SWAT Medics and respond using Squad 1 (an ALS equipped ambulance which also carries some light rescue gear and other specialty tools) The front-line members of the department are represented by the San Luis Obispo City Firefighters' IAFF Local 3523.

[36] The Water Resource Recovery Facility treats 4.5 million gallons per day and is currently undergoing a plant upgrade expected to be completed in 2021.

Following a failed effort [citation needed] by R. J. Reynolds Tobacco Company to defeat the ordinance, the City Council voted 4–1 in favor on June 19, 1990, with only Mayor Ron Dunin dissenting.

As a result, on August 2, 1990, San Luis Obispo became the first municipality in the world to ban smoking in all public buildings, including bars and restaurants.

[38][39][40] In April 2010, San Luis Obispo strengthened its anti-smoking legislation, making smoking in public, excepting for certain conditions, a citable offense beginning on June 20, 2010.

This ordinance poses a fine of $700 for the hosts of gatherings with more than 20 people on private property that create a substantial disturbance in a significant amount of the neighborhood.

The district also operates several schools outside of San Luis Obispo in nearby Avila Beach, Edna Valley, Morro Bay, and Los Osos.

The doctor's office on the corner of Santa Rosa and Pacific streets is one of very few commercial buildings designed by Frank Lloyd Wright.

[53] One of the largest Mardi Gras parades west of the Mississippi was held in San Luis Obispo, but canceled in 2005 because of difficulties related to crowd control and alcohol consumption.

[55][56] San Luis Obispo has been home of several other events, including a stop on the way of the Olympic Flame Relay, the Tour of California bicycle race, Cinco de Mayo celebrations, and a long-standing Christmas Parade.

The summer of 2007 was the opening concert of the Forbes Pipe Organ, which was built elevated into a side wall of Harmon Hall and required the donation of a further $3 million for purchase and installation.

[59] The San Luis Obispo Museum of Art began in the 1950s when a small group of artists, educators and enthusiasts established the foundation.

[69] Greyhound closed its station building in San Luis Obispo on March 12, 2009; it still serves the city via a bus stop on Railroad Avenue.

[70] The SLO Car Free program provides an online one-stop-shop for all car-free vacationing needs from bus schedules and bike maps, to discounts on transportation, lodging, and attractions.