Practical and important: you are in one of the best regional food cultures in the United States, and it would be a shame to drive through it eating gas-station sandwiches.
Northern New Mexican food is its own thing. It is not Tex-Mex and it is not Mexican food; it is a distinct cuisine built over four hundred years out of Pueblo, Spanish and Mexican cooking, and its foundation is chile.
You will be asked a question: red or green. That is the official state question of New Mexico — genuinely, it was adopted by the legislature — and it means which chile sauce you want on your food. Green is roasted green chile, usually brighter and often hotter. Red is the same pods left to ripen and dry, then made into a deeper, earthier sauce.
If you cannot choose, say Christmas. That means both, one on each half, and nobody will think less of you.
Things to look for: green chile stew, carne adovada, enchiladas served flat and stacked with a fried egg on top rather than rolled, sopaipillas — puffed fried bread that arrives with honey — and posole.
One warning. New Mexico chile can be genuinely hot, and 'mild' here is calibrated to people who grew up on it. Ask before you commit.
And in late summer, the whole state smells of chile roasting in drum roasters outside the grocery stores. If you hit that, you have hit it right.
Photo: Chitrapa · CC BY-SA 4.0