Las Fuentes, in my opinion, is really the best restaurant in Yucaipa so it gets 5 stars because it is good and it's one of your best options in Yucaipa for a nicer ambience dining experience.
There are not many "fancy" options here and it's nice to rely on Fuentes b/c the food is never delivered to your table with a long wait and the quality is very consistent over the years.
Great Mexican food, good service, and good atmosphere (rustic tile, rustic painting, nice little courtyard for outside dining, too). Awesome margaritas and sometimes they have music.
The menu has your typical Mexican restaurant choices tasty fajitas, burritos, tacos, enchiladas, good soups, etc. (go for the tacos asados with grilled chicken -- awesome) in addition to a special section of Fuentes especiales (which are always on the menu -- good carnitas -- great Garlic-shrimp, etc dishes). Fajitas for two is a great deal. They are never stingy on the chips and the house salsa, I think, is pretty good and spicy.
This restaurant has been in Yucaipa for about 6-7 years now, so it is pretty established and that says a lot. It is located at the Shopping plaza with Von's/Denny's/Starbucks at the corner of Oak Glen & Yucaipa Blvd. It's a chain and is also located in Redlands, next to the Krikorian Movie Theatres. You can't go wrong here...my only complaint would be the bar area in Yucaipa is smaller than Redlands -- would be nice if it had more chairs!