The elderly couple with a particular affinity for Whataburger can cross visiting every one of the burger joint’s locations off their bucket list.

That’s right; a retired couple in their seventies from Rockport finished the last leg of their Whataburger challenge—to visit every one of the chain’s 729 locations across ten southern states—in Dallas Wednesday.

Karl and Carol Hoepfner, married for 55 years, decided to start their Whataburger quest last April while Carol was undergoing a 23-day radiation treatment for a rare form of eye cancer in Houston.

They wanted to keep busy by doing something fun to keep their minds off Carol’s illness. The El Paso Times reported, “After treatment, they visited all 90 Houston-area Whataburgers and thought that if they could do 90, they could do all of them.”

So, they set off in their van to visit restaurants in Florida, Arizona, New Mexico, Oklahoma, Louisiana, Arkansas, Mississippi, Alabama, Georgia, and their native Texas, which boasts the largest number of Whataburgers by a long shot—597, according to a 2011 count. Sometimes, the couple would visit up to twenty stores in one day.

The Hoepfners’ love affair with Whataburger stretches back to 1963, when they made their first trip to the fast food joint, wrote an MSNBC food blogger. In those days, Karl and Carol were stationed in San Angelo, both retired Air Force master sergeants in search of good, cheap eats. Their two children love the chain too: both of them worked at an Austin Whataburger, and their son once earned the distinction of being name Whataburger Employee of the Year, Karl told a Food Republic writer.

In November 2010, Karl won Whataburger’s Biggest Fans contest with his 700-word essay about how he had visited the chain at least 7,000 times. To thank him for his faithful patronage, Whataburger awarded the 75-year-old $8,600 in gift cards. But as much as Karl likes his burgers, it seems he values philanthropy even more.

“We gave back $7,000, and Whataburger gave us 1,000 gift cards at $7 a piece,” Karl told the El Paso Times. “We give those out along the way to the homeless and the needy. We’ve fed over 2,000 people so far. We thought why not give it back to people who need it the most.”

While on their journey, the two stuck to their usual orders: Karl gets a Whataburger with grilled onions and jalapenos and Carol prefers a Justaburger with grilled onions, according to the Corpus Christi Caller-Times. Since they try to watch their weight, they usually avoid french fries and onion rings, and they also like the chain’s salad offerings.

Over the past year, the Hoepfners have been greeted by friendly employees and showered with gifts, including an orange-and-white frosted cake from a Corpus Christi Whataburger. And yesterday, Whataburger presented the couple with a new ride as a token of the company’s appreciation—a black minivan wrapped in a red ribbon.

KVUE was on the scene for the Hoepfners’ last restaurant visit in Dallas and reported that Whataburger had even included a personalized message on the side of the van’s door: “I’m Whataburger’s BIGGEST FAN. But you can call me Carol.”