Jurupa Valley is a city in the northwest corner of Riverside County, California, United States. It was the location of one of the earliest no…Jurupa Valley is a city in the northwest corner of Riverside County, California, United States. It was the location of one of the earliest non-native settlements in the county, Rancho Jurupa. The Rancho was initially an outpost of the Mission San Gabriel Arcángel, then a Mexican land grant in 1838. The name is derived from a Native American village that existed in the area prior to the arrival of Europeans.