That’s the United States. Down Mexico way, not so much. The Bell has attempted to “run for the border” two times, but was turned back on both occasions. You’d have better luck selling ice at the North Pole. Or Pizza Hut in Italy.

Taco Bell started test-marketing Doritos Locos Tacos — taco shells made from Nacho Cheese Doritos chips — a year ago in small test markets like Fresno and Bakersfield, Calif., and Toledo, Ohio. Small towns have all the luck. Sales went through the roof … then the stratosphere, then straight into orbit. Since then, taco fans have been rubbing their hands waiting for the national rollout.

Well, Doritos Locos Tacos are finally here.

And here’s the blueprint: a hard taco shell stuffed with standard-issue Taco Bell seasoned ground beef, chopped lettuce, diced tomatoes, real cheddar cheese and reduced-fat sour cream.

It’s funny when a fast-food chain says ” ‘real’ cheddar cheese.” It’s like Clark Griswold having to ask Cousin Eddie in “National Lampoon’s Vacation”: “Real tomato ketchup, Eddie?” Just say “cheddar cheese.” I’ll trust you, drive-thru taco maker.

Total calories for a Doritos Locos Taco: 170. Fat grams: 9. Sodium: 340 mg. Dietary fiber: 2 g. Carbs: 13 g. Manufacturer’s suggested retail price: $1.29. That’s pretty easy on the calories, fat and wallet.

The Doritos Locos Tacos Supreme, about 50 percent bigger, is $1.69. While you’re crunching this taco, crunch the numbers. Supreme is the better value.

Just how locos are these tacos? Using Nacho Cheese Doritos to make a taco shell isn’t that wacky an idea. Doritos aren’t exactly hard to find. They’re available in every supermarket, convenience store and bus station vending machine.

Using snacks and cereals in cooking isn’t breakthrough technology, either. Fried-chicken joints have been rolling in cornflakes, potato chips and Cap’n Crunch for decades. Never heard of Cap’n Crunch fried chicken? Kids love it. Especially those big kids called “men.”

Doritos Locos Tacos shells are darker than regular Taco Bell taco shells, and they’re lightly dusted with orange cheese powder. They’re served in special paper taco trays, but if you eat them commando, your fingers will turn orange. We’ve been there with Cheez Doodles.

Doritos Locos Tacos are zippier and more flavorful than regular flour tacos because Nacho Cheese Doritos have a kick. Plus, these tacos are piggybacking on a crazy-popular snack food. Everybody loves Doritos. They’re crunchy and spicy and salty. Everybody loves tacos. They’re meaty and cheesy and sour-creamy. You’d have to be locos NOT to put them together.

And you’re totally locos if you think Taco Bell is stopping here. The Bell reportedly is dabbling in Cool Ranch Doritos Tacos next.