The demographics of the Cucamonga Valley have been shifting in recent years. The population of European Americans, who once constituted a large majority, is on the decline while the population of Latinos and African Americans is growing . Unlike most of Southern California, there is not a particularly strong representation of Asian Americans in the Cucamonga Valley, although it is steadily increasing. Rancho Cucamonga has the highest population of Asian Americans in the Cucamonga Valley, at 9.00 percent of the population.
Historic U.S. Route 66, as Foothill Boulevard, runs east-west through the region. Other major surface streets include Base Line Road, Arrow Route, 4th Street/San Bernardino Avenue, and Valley Boulevard running east-west and Archibald Avenue, Sierra Avenue, and Riverside Avenue running north-south.
