Tresierras Supermarkets was founded in 1944 in San Fernando, CA, originally called "Frank's Market" moved the store in 1947 to San Fernando and renamed Tresierras Market. In 1958, Francisco and Pilar's sons, Daniel, Richard and James took over operations. Tresierras Supermarkets operates 4 full-service Latino supermarkets in Ventura and Los Angeles counties