Bloomington is an unincorporated census-designated place (CDP) in San Bernardino County, California, United States. The population was 23,851 at the 2010 census, up from 19,318 at the 2000 census.
Though now unincorporated, many of the town's political activists are pushing for Bloomington to attain cityhood, while the nearby cities of Rialto and Fontana are attempting to annex the community. The incorporation effort is led by the BIC, the Bloomington Incorporation Committee.
Bloomington was originally developed as part of the land holdings of the Semi-Tropic Land and Water Company which was formed in 1887. In 1907, the Riverside Portland Cement Company built a large plant near Crestmore (South Bloomington) and to provide transportation for employees built a standard gauge railroad to Riverside. On May 20, 1911 the line was opened to Bloomington. The original community, known as Crestmore, is generally located between Locust Avenue and Larch Avenue, south of Jurupa Avenue, extending to the County line. The Pacific-Electric Crestmore Line (Riverside-Rialto) provided local service for many years. The Semi-Tropic Land and Water Company (now known as West Valley Water District) laid out the town sites of Bloomington, Rialto, Fontana, and Sansevaine. The town site for Bloomington, after being surveyed in April, 1888, was bounded on the north by Valley Boulevard, on the south by Slover Avenue, on the east by Larch Avenue, and on the west by Linden Avenue. Presently, part of the community is still rural and many residents continue to keep and raise animals.