I'd like to post a very quick thanks to Canon Fowler whose wonderful discussion of Sonoran food has helped me understand more the cuisine of the Yuma area and has made possible my posting on the Mexican food of Yuma.
The cuisine of Yuma seems based on Sonoran-but changed in several ways. Yuma is located in the rich farming area of the Colorado River valley and not far from the Imperial valley and the Mexicali region. So while flour tortillas are the local favorites, corn tortillas can be found. Albondigas is very popular, but Caldo de Res-a soup with chunks of beef and large chunks of vegetables like corn on the cob, squash, carrots, potatoes, celery, etc. is even more common. In fact, the local Mexican food seems to feature soups (caldos) from birria and caldo de pollo to menudo and posole. To someone used to Americanized Mexican food, this preference for caldos would seem unusual. Asadas, carne in particular but also pollo, are also local favorites, as are chilies, both verde and colorado. Authentic fast food Mexican (and yes, there is a lot of that here) usually doesn't feature the soups, but focuses on burritos and tacos mostly. Also, a taco here is a soft corn tortilla with meat and salsa or other condiments. If you want a crisp shelled taco, you must order a folded taco, and what other places call taquitos are here called rolled tacos.
See also my posting on specific Mexican restaurants.