According to archaeological evidence and historical records, the area we know today as the Sepulveda Basin Recreation Area was home to ancestors of members of the San Gabriel Band of Mission Indians (Gabrieleno Tongva) and the Fernandeño Tataviam Band of Mission Indians (FTBMI). When the Spanish settlers arrived, they and other Indigenous groups were enslaved at Mission San Gabriel and Mission San Fernando. Enslavement decimated these tribes and by the time of the Secularization Act of 1834, which returned Mission land to its inhabitants, hundreds of thousands of Native Americans had been reduced to approximately 500. Efforts to reclaim their homelands are noted in the FTBMI website:

“After the Missions were secularized by Mexico, approximately 50 surviving Fernandeño leaders negotiated for and received several land grants amounting to over 18,000 acres (10% of the San Fernando Valley) that were held in trust by the Mexican government. These land grants included Rancho El Escorpion (Chatsworth), Rancho Encino (Encino), Rancho Cahuenga (Burbank), and Rancho Tujunga (Tujunga), and were meant to be preserved in the American period.” The Sepulveda Basin and the suburb of Encino to the south fall within the boundaries of Rancho Encino.

With the end of the Mexican-American War in 1848, what we now know as California became part of the United States and the Treaty of Guadalupe Hidalgo offered formal protections to former citizens of Mexico – Indigenous and European. However, as neither Mexico nor the United States had considered the original inhabitants of the continent to be citizens, and both countries had seized Native land using the law and genocide, the California Constitutional Convention quickly moved to deny Native people of any rights, and land grants were disputed.

The FTBMI website further notes: “On June 1, 1876, a group of Fernandeños and married relations purposely occupied their homelands land to test land title. They were taken to court by ex-Senator Charles Maclay. In 1878 the judge, a relative of Maclay, reaffirmed Maclay’s rights to the land. As a result, the Fernandeños were evicted from their homelands. In 1885, U.S. Special Attorney for Mission Indians, Guilford Wiley Wells represented Rogerio Rocha and the Fernandeños in an official government capacity to prevent the Tribe's eviction from Indian land. On November 2, 1885, Wells’ petition was denied in Los Angeles County Superior Court.”

With almost two million inhabitants today, the San Fernando Valley epitomizes suburbia in the public imagination. However, for much of its early post-colonial history, the region was a sparsely populated agricultural hinterland, just over the hill from Los Angeles. Even as LA’s urban sprawl expanded through the late 19th and early 20th centuries, the Valley remained largely rural and didn’t experience its full transformation until the latter half of the 20th century. As the region’s population continued to grow, farmland gave way to suburban development, providing homes for the large number of men and women who worked in the rapidly growing aerospace and screen entertainment industries. As a result, from 1950 to 1960, the Valley went from the 25th to the 9th largest urban center in the nation.