Though well inland from the Pacific Ocean, Solano County was easy for Spain to access during the early days of exploration in northern California. The county’s southern boundary is Suisun Bay, which is part of the San Francisco Bay complex. Five years after having discovered the area that became San Francisco, Spain was also exploring the Solano County area.

Creating settlements and a military presence wasn’t an urgent matter for Spain. It had other priorities. From the Presidio in San Francisco, Spain controlled access to the bay and thus all lands beyond. From 1776 to 1783, Spain assisted the United States in its war for independence. In 1808, Napoleon waged war on Spain. That same year instability arose in New Spain, continuing to 1821, when the colony gained independence, becoming Mexico. 

It was Mexico which began to emphasize developing Sonoma and then Napa and Solano. This was a reaction to concerns about the potential for Russian expansion southward. Russians had established Fort Ross on the Sonoma Coast in 1812, followed by smaller settlements inland, and even a seal-hunting station in the Farallon Islands off the coast of San Francisco.

In 1835, General Mariano Vallejo, who took command of San Francisco’s Presidio in 1833, took over the mission in Sonoma. He also designed the town and moved the majority of his forces there from San Francisco. Wanting a buffer against the Russians, Mexico began issuing massive land grants for areas beyond Sonoma to encourage settlement and development.

One of those grants went to “Chief Solano.” A Native American of the Suisunes tribe, he was a child named Sem-Yeto when either captured or merely sent to the mission in San Francisco, in the aftermath of the Moraga raid on the Suisunes in 1810. He was raised and converted to Christianity at that mission, taking the name Francisco Solano in honor of Saint Francisco Solano, one of Spain’s first missionaries in the New World. 

In 1823, Francisco Solano/Sem-Yeto went to Mission San Francisco Solano in Sonoma, along with other Suisunes who had  been living at the mission in San Francisco, to help build it and to add to the population. He became a leader of his people there, hence the moniker “Chief Solano.” In 1835, he formed an alliance with General Mariano Vallejo and Mexico. He also helped establish an 1836 peace treaty between Mexico and most of the local Native American tribes.

Land grants were vital to the development of the area, but not successful in consolidating Mexican control. Unrest in the area grew. The Russians sold Fort Ross to John Sutter, an Austrian immigrant with both Mexican and American citizenship, after the Mexican governor failed to secure it for Mexico. The Bear Flag Revolt erupted in Sonoma in 1846, led by Americans hoping to create an independent republic. The United States took possession officially in 1848 and in 1850, after California became a state, Vallejo actually became one of its first state senators.

After California became part of the United States, , development progressed rapidly. Solano County’s location made it an important trade and travel hub, as well as a substantial  producer of food, and eventually grapes, for surrounding areas. Its central location also led to its town of Vallejo succeeding San Jose as state capital in 1852.One year later, the capital moved to Benicia, also in Solano County.

Viticulture arrived in Solano County in 1858 when John Volpyka planted vines in Green Valley. Vineyard acreage expanded fairly rapidly, as it did in Sonoma and Napa Counties. But, in the 1870s, a major setback arose with the onset of phylloxera.

Fortunately, the innovation of grafting phylloxera-resistant North American rootstock also came about in the 1870s. Replanting with grafted vines led to a repopulation of vineyards, and in 1880 Solano County’s first wineries were established. 

Success was short-lived, however. As European vineyards began to recover, demand for American wine abroad declined. At home, the temperance movement began to make its presence felt. By 1905, saloon owners in Solano County had stopped opening on Sundays. Just four years later, Vacaville passed a law making it a dry town. Prohibition went into effect nationwide in 1920, devastating the California wine industry.

The first winery established in Solano County after Prohibition was Wooden Valley Winery in 1933. But overall, recovery was slow. And, as before, Solano County’s role was primarily as a source of grapes rather than finished wines. Roughly 90% of the county’s winegrapes are still sold to out-of-county producers, mostly for blending.

The early 1980s saw the establishment of the area’s AVAs: Solano County Green Valley (1982), Suisun Valley (1982), Clarksburg (1984), and Wild Horse Valley (1988).

Solano County has recently suffered from forest fires. In 2020, the Hennessy fire ravaged several counties and in Solano County, it destroyed homes, rangeland, and one winery.

Stone artifacts found in the area date back to this era

Spanish navy reaches what is now Solano County for the first time

Moraga raid, the first Spanish (military) land expedition in the area

Mexico establishes Mission San Francisco Solano in what is now the town of Sonoma

Mexico begins settling areas north of the bay, beyond Sonoma

Suisun Rancho granted to Chief Solano

Six Mexican land grants cover the area now Solano County: Suscol, Suisun, Tolenas/Armijo, Los Putos/Vaca/Pena, Rio Los Putos/Wolfskill, and Ulpinos/Bidwell

John Wolfskill becomes the first recorded American settler in what is now Solano County

United States military establishes control; Solano County area considered part of Sonoma Territory

Ferry service established across Carquinez Strait

Town of Benicia founded

- California becomes a state, with Solano one of the original counties.

- Town of Vallejo established

- Chief Solano dies

Vallejo becomes California state capital

Benicia becomes state capital

John Volpyka, an Austrian immigrant, plants first vines in Green Valley

California Pacific Railroad reaches Vallejo

Phylloxera begins to affect Solano and Napa County vines

Wineries established in Green Valley and Cordelia

Vines planted in Wild Horse Valley

Saloon owners stop serving on Sundays

Vacaville bans sales of alcohol


Wooden Valley Winery is first post-Prohibition wine producer in Solano County

Bogle family plants 10-acre vineyard in Clarksburg area

Solano County Green Valley AVA and Suisun Valley AVA established

Clarksburg AVA established

First modern vineyard established in Wild Horse Valley

Wild Horse Valley AVA established