When Spanish settlers entered Suisun Valley in the early 1800's, the hills around Bella Vista Ranch supported small bands of Indians who lived in grass huts and subsisted on acorns, berries, roots and insects, with fish and small game. Possibly these Indians were associated with a larger settlement, located in grassy fields below the sandstone bluffs of Rockville, which an 1807 Spanish report calls the village of the Suisune.
Some say Suisun is a Miwok Indian word that means, "where the west wind blows". Actually, the Suisune were only distantly related to the Miwoks, and they, along with the nearby villages of Tolen (Tolenas), Putato (Putah Creek), and Karkin (Carquinez), called themselves Patwin, meaning "people". Most likely, the true meaning of Suisun has long since been forgotten.
In 1817, a Lieutenant Sanchez left San Francisco and entered the Valley of the Suisune with a band of soldiers "to explore the new country and reduce the natives to Christianity". He reports that the Indians ambushed his men and that when he finally caught up to them at Suisun they set fire to their own village and committed suicide by throwing themselves on the flames. More likely, Sanchez and his men massacred them.
Survivors of the massacre were sent in 1823 to the new Franciscan mission of San Francisco Solano de Sonoma. A young Suisune there named Sem-Yet-Ho, which means "fierce one with the strong hand", was a giant of a man who at six feet seven inches tall towered over his Indian peers. He took the name Francisco Solano at baptism and by virtue of his stature and command of the Spanish language became a leader of his people.
Called both Chief Solano and Chief Mighty-Arm, Sem-Yet-Ho was an ally of General Mariano Vallejo and was instrumental from 1834 to 1838 in helping Vallejo stem Indian uprisings by the Yolo and Guappo tribes. However, plagues of small pox and cholera decimated the Suisune and reduced their numbers from 40,000 in 1835 to 200 pitiful survivors by 1841. Solano himself died a few years later and his people were all but extinct by the 1920's. Yet, their legacy lives on in the valley that today bears their name.