Prehistoric cultural affiliation(s) include Cahuilla, European, Native American, Luiseno, San Dieguito, Early Playa, Malpais, Patayan, Amargosan and Qawi?Siktem dating back to 16999 BC.
The famous person Francisco Estudillo is associated with one of more of the Riverside County historic places.
Some of the country's most noteable architects helped create the Riverside County places including S.P.,L.A.,& S.L. R.R., Rocco Garbani, Bacon & Ashenfelter, Franklin P. Burnham, Franklin Pierce Burnham and S.L. Bloom. Prominent architectural styles found in Riverside Country are Classical Revival, Italianate and Late Victorian.