The 48-year-old man was sleeping near the restroom when he was abruptly awoken by two men holding him down, according to police.
One of the men held a box cutter to his neck as they robbed him of his cell phone, wallet and bicycle.
The two men fled westbound on Orange Way and then north on Rosena, according to police reports.
Both suspects are described only as thin white males wearing dark colored shorts. Both were wearing hoodie type sweatshirts, one dark colored and the other was grey.
Anyone with information about this incident is encouraged to contact the Fontana Police Department at 909-350-7740 or anonymously at 909- 356-TIPS (8477).