Five years ago, my friend Kate Erickson sent me a photo of a piece of artwork that she'd spotted on the wall of a combination KFC-Taco Bell in Billerica, Massachusetts. Since then, I have thought about it approximately once a week. The mural, which takes up the better part of a wall, is a richly detailed masterpiece celebrating the confluence of American fast-food culture that can be found at your neighborhood KFC-Taco Bell outpost.

On the left, we see the Southwest – a bleak but bounteous land of cheap burritos. While Taco Bell's first location was in the Los Angeles suburb of Downey, California, the towering buttes and saguaro cacti are reminiscent of the Sonoran Desert. On the right, the painting depicts the rolling green hills and farmhouses of Kentucky, made slightly surreal with the presence of drumstick-shaped blimps overhead.

Based on the boxy Jeep Cherokee-style car in the foreground, the painting appears to date to the early 1990s.

"I think the appeal is that it's really unironic and earnest, and yet manages to end up being incredibly kitsch," Kate recently explained when I asked her why she'd been drawn to the painting in the first place.

As a Ph.D. student in visual culture, she had some other observations:

"There's also the undertone that it could potentially be this really bleak commentary on consumerist America, placed in situ within the very sort of global commercial enterprise that drives American interests – potentially at the cost of the traditional 'American dream,' which this mural depicts a perverse version of. So basically, I find its enigmatic motive, and the fact that it potentially reveals more about KFC as a global brand than it means to, very compelling."

Even though Taco Bell is part of a multinational corporation whose franchises are so ubiquitous that they can even be found on military bases in Iraq, I mistakenly assumed that the painting was a one-of-a-kind. Then, in January, my boyfriend and I were driving to New Mexico for the weekend when he pulled over at the KFC-Taco Bell off Interstate 10 in Benson. I stayed in the car. A few minutes later, he came back and told me that there was something inside that I had to see.

A burrito doubles as a bridge in the background of the painting. Antonia Farzan

Once my shock had worn off, and after taking approximately 12 million pictures, I spent the rest of the drive researching Taco Bell interior art with the help from some kind people on Twitter.

As it turns out, numerous other copies of the mural have been spotted in the wild. One is in Alpharetta, Georgia. Another was uploaded to Flickr by a man named Will who goes by the username baltimore_retail and seems to spend his spare time taking photos of mercantile establishments in greater Baltimore.

A now-defunct punk band named Brain Tumors reported spotting the painting on a drive from Denver to Omaha in August 2012. Vocalist Drew Ailes described it as "an untouched gem that the next batch of planet-destroying cretins will unearth thousands of years from now."

He also added, "I was tempted to vandalize this piece of art by scribbling the implied racial segregation but resisted."

A detail from the mural. Antonia Farzan

In another recent sighting, a German blogger visiting Cannon Beach, Oregon, came across the painting in the nearby town of Seaside.

"Im vielleicht schlechtesten Taco Bells – KFC unserer USA Geschichte essen wir Burrito und Chicken, kein Foto wert," the blogger, who goes by "Moglu" for anonymity, wrote.

According to Google Translate, this means, "In perhaps worst Taco Bells – KFC of our USA history, we eat burrito and chicken, not worth a photo."

Another version of the mural can be found at a KFC-Taco Bell in Lakewood, New York. It depicts an anonymous city that's been taken over by fast-food franchises – just about everything is emblazoned with KFC and Taco Bell logos, from the crosswalk to the mailbox to the clouds in the sky.

All the paintings are undated and unsigned, and trying to identify the artist has become an ongoing personal quest. Since first learning of its existence, I've periodically called the Billerica, Massachusetts, KFC-Taco Bell to see if anyone there knows about the mural's origin story – and to make sure that it's still there. According to the notes saved to my phone, I was told by one employee that it's been there for at least 15 years. That was five years ago. Since then, no one has been able to tell me anything about the painting.

Part of a series of paintings that Mark T. Smith did for Taco Bell in 2003. Mark T. Smith

Perhaps the most prominent artist working in the American fast- food sphere is Mark T. Smith, a Miami-based painter who created a series of original acrylic paintings for Taco Bell in 2003.

When one of those paintings got stolen from a Taco Bell in Westlake, Ohio, it made international art world news. Local police were surprised to find out that it was worth $800.

To this day, a thriving black market for Smith's paintings exists on Reddit, where anonymous Taco Bell employees sell copies that they claim to have acquired through legal means.

But Smith confirmed in an email to Phoenix New Times that the mural in Benson and Billerica isn't his work — not surprising, since his style is markedly bolder and more abstract. He doesn't know who the other artist is, he said.

In Benson, a very helpful cashier took down my name and phone number and promised to call if any information turned up. Meanwhile, I contacted Yum Brands, the corporate parent of KFC and Taco Bell. A media relations representative asked me to send over a photo so that they could ask the franchise owners, but noted that the store might have changed hands at some point in the past two decades.

Do you know who the mystery artist is, or have you spotted the mural at your local KFC-Taco Bell? Please send me your tips.