Oh Amanda, I know how awful this feels. Do take and post flyers at all the nearby vets and animal shelter, street corners... And call or stop by the animal shelters daily. Walk around the neighborhood and call to her every day. Cats can get stuck in some interesting places, most often nearby.
We had one cat take off on moving-in day during all the ruckus. So she was in a totally new environs and managed to survive hiding from coyotes under an abandoned trailer, in a canyon, until we found her three days later when we were out walking and calling one night after work and heard her faint meows. Another one was missing for a couple of days - right next door, he had somehow gotten himself into and trapped in a meshed screen area on the side of their house and we finally heard his meows. That same cat once went missing, and was presumed gone, for TWO MONTHS when he showed up on the doorstep one morning at 5:00 am. Cats are very resourceful.
Sending positive thoughts that Tortilla finds her way home soon.
2001 Trek 7500 FX, converted to a hauler - Serfas
200? Marin hybrid - Selle San Marco
2004 Trek 5200 - Avatar
2011 Trek 6.2 Madone - Ruby