Ancient artifacts discovered by archaeologists suggest that the city of Rialto was settled prior to the year 1500. Such artifacts, now found at the Rialto Historical Society, indicate that the Serrano Indians lived in the Rialto area between 1500 and 1800 AD. No record was left behind to suggest the eventual relocation of this group of people, therefore it is assumed that they were most likely overtaken by disease and assimilation into other communities in the surrounding countryside. By the year 1854, the area had been developed into a haven for vineyards, citrus groves and ranches.Early residents of Rialto prided themselves on the cultivation of muscat grapes, which became an important contribution to the economy. An adobe building from this time period, which had many uses over the years, is the oldest building in Rialto and is now restored in Bud Bender Park. It is not clear how Rialto got its name, although one story suggests that "Rialto" is a contraction of rio (river) and alto (high). The other story is that the area was named after the Rialto Bridge located in Venice, Italy, which resembled the one that once crossed the city. In either case, the bridge soon became a community symbol and became known as the "Bridge of Progress."
Today, Rialto is home to three major regional distribution centers: Staples, Inc., which serves stores across the entire West Coast of the United States, Toys "R" Us, and Target in the northern region of the city. One of the United States' largest fireworks companies, Pyro Spectaculars, is also headquartered in Rialto. As of the 2006 demographic, the city had an estimated population of 99,467.
Over time, Rialto has recovered from boom and bust and matured with new store fronts, updated buildings and rising modernization. Despite its location within a very large metropolitan area, Rialto has maintained an atmosphere of a quiet suburban community, especially compared with nearby San Bernardino and Ontario. Its proximity to greater metropolitan areas such as Los Angeles and Orange County has made Rialto a bedroom-community for those who seek a quiet place to live and a relatively short commute to work. As a commitment to the city's housing charm, the City of Rialto is in the process of developing a 1,500 acre master-planned community with a variety of housing choices and new job opportunities. The development, named "Renaissance Rialto", will not be underway until 2008 and will likely take 5 - 10 years to complete.