Ontario is a city located in south west San Bernardino County, California, United States, 35 miles east of downtown Los Angeles. Located in the western part of the Inland Empire region, it lies just east of the Los Angeles county line and is part of the Greater Los Angeles Area. Wikipedia

Santa Clarita, officially the City of Santa Clarita, is the third largest city in Los Angeles County, California, United States and the eighteenth largest city in the state of California, based on the population estimate from the California Department of Finance. Wikipedia