Fontana is a city of almost 200,000 residents in San Bernardino County, California. Founded in 1913, it remained essentially rural until World War II, when entrepreneur Henry J. Kaiser built a large steel mill in the area. It is now a regional hub of the trucking industry, with Interstate 10 and State Route 210 transecting the city from east to west, and Interstate 15 passing diagonally through its northwestern quadrant. It is home to the largest of the San Bernardino County system libraries, a renovated historic theater, a municipal park, and the Auto Club Speedway on the site of the Kaiser Steel Mill. Fontana also hosts the Fontana Days Half Marathon and 5K run. This race is on record as the fastest half-marathon course in the world. The U.S. Census estimated Fontana's population at 170,099 in 2006, and the California State Department of Finance estimated it at 190,356 in 2010.