Metrolink to Fontana then bus.
6$ day pass for the foothill line take the silver streak bus from Union station by the side of the freeway all the way at the end of the side walk median last bench , don't don't get confused with the silver line bus it is very different. Get on silver line get off at Montclair Transit center the last stop ! Don't fall asleep it turns back around to LA goes in a circle. At Montclair Transit center find the #290 bus to Arrowhead Regional , exit and walk a little to Arrowhead, if they don't except your day pass and have no cash , 99% of the time the driver will just take you courtesy because it's a route to a hospital 😉
Amtrack is way cheaper 13 bucks and then you get on a different bus that's covered by the 13 bucks...
Call Amtrack
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