We just gave some hints to a roadfooder coming the opposite Direction…check the thread.
My suggestions
Mesquite NV, the Oasis Casino…One of the older ones, nice cool buffet Much less stressful than any of the Vegas stops.
Cedar City Utah. West on Rt56 less than a mile…Market Grill. A folksy cafe with very good ribeyes for cheap.
Fruita-Grand Junction- Fresh Fruit is coming into season…Get off the I-70 long enough to hit a couple of the fruit stands. Outstanding peaches, Plums, Apricots etc.
Empire CO, Jenny’s Cafe. Another great foodie place with inexpensive meals that will satisfy you for sure.