Ryan Carey-Mahoney

USA TODAY

Hold on to your chalupas, Taco Bell fans, because the chain's latest challenge is going to make you loco.

To promote its new dollar menu, the fast-food giant has announced the "Eleven Everlasting Dollars" challenge, with an everlasting prize: a lifetime of Taco Bell food.

Over 11 days, Taco Bell is releasing 11 specialized dollar bills, marked by specific serial numbers, in 11 U.S. cities for fans to search for. The contest began Tuesday in Los Angeles, followed by Chicago on Wednesday, and will continue in nine other locations until the bills are found.

Eager customers can check the website's interactive map, updated daily, to find the serial numbers and cities in play.

Harley Morenstein of YouTube sensation Epic Meal Time and comedian James Kirkland unveiled the campaign in a video, in which they're shown holding a metal briefcase filled with the precious digits.

The hunt won't be easy. According to the official rules, the chances of finding one of the 11 dollar bills are about 1 in 2.4 billion.