Organizers had about a thousand tickets to give out each day to area residents who said they had no other options for care.
Sherry Moreno spent a night under a tarp in the rain waiting to see her volunteer doctors.
MORENO: "You may have to stay outside all night and wait in long lines, but you know what, it's worth it. OtherwiseI wouldn't be able to get any of this stuff done."
Moreno needs dental, medical and eye care today.
She has a job, but she says the health insurance is too expensive.
HANOSH: "You got a couple of broken teeth in here… "
Dr. Scott Hanosh examines her teeth. He's a dentist in Paradise, near Chico. Here at CalExpo today, he says they're mostly treating people in pain.
HANOSH: "We've done extractions on teeth that are non-salvagable, and we've done fillings on teeth that can be saved."
Before she saw the dentist, Moreno got new eyeglasses.
She says they will immediately change her life.
MORENO: "I'd still be driving around, squinting, trying to see the street signs. I'd be getting lost!"
The four day event ends Monday and was organized by a group called Remote Area Medical or RAM California.
They hope to hold more free medical care events in more cities throughout the state.