It's been more than 50 years since turkey farmer Eddie Velo dropped by to sulk inside the Keller brothers' blacksmith shop in Rothsay, Minn.

Velo's farmhands had done it again. Quit. Right before it was time to shovel 12 inches of turkey dung out of five two- story barns.

Velo's dilemma got brothers Cyril (Cy) and Louis Keller thinking. It wasn't long before they surprised Velo with a sketch of an innovative two-wheel-drive contraption that they thought just might scoop dung and navigate a barn's narrow corners like a champ.

Six weeks later, the first Bobcat skid-steer loader was born. It wasn't long before the Kellers' blacksmithing days of sharpening plows and building farm trailers were behind them. They built six loaders, including one with an extra-strong manure fork, fashioned from the bars of the Rothsay jail.

Lester Melroe of Melroe Manufacturing -- a North Dakota ag equipment firm that employed the brothers' uncle -- invited the brothers to demonstrate their Keller Self-Propelled Loader at the 1958 Minnesota State Fair.

The crowds grew so big "we didn't have room to operate," said Cyril, 86.

"Melroe was really surprised. We had 100 people at a time trying to get up to see it. On our third day, here comes Melroe with a handful of [Melroe] stickers, putting them on our machine," recalled Louis, 85. "We were there to sell our machine to him. So we thought, 'This was pretty good.'"

Fast-forward 50 years, and the business partnership struck that day has turned into an international hit. This week, the Keller brothers celebrated the 50th anniversary of their Bobcat invention as the company made its 750,000th loader in Gwinner, N.D. (In 1969, Melroe sold to Clark Equipment Co., which became part of Ingersoll Rand in 1995.)

(South Korea's Doosan Infracore acquired the company in 2007.)

The Kellers spent Friday signing autographs for 400 dealers and customers at the Mall of America, where 50 Bobcat loaders, mini loaders and other machines sparkled in the sun.

Now they're everywhere

The Kellers' mighty little machine, which turns on a dime and swiftly alters its center of gravity, is now a ubiquitous four-wheel-drive staple for farms, ranches, construction sites, foundries, shipyards and landscapers around the globe.

"I'd like to get a little autograph," said Tri-State Bobcat salesman Arin Laugtug, presenting Cyril with a photo of a customer who tattooed a skid-steer loader on his backside.

"I owe a lot to Bobcat," said Oranzu Oevering, shaking Cy's hand. "We wouldn't have had the business without Bobcat" he said, noting that his father sold used Bobcats for 39 years.

It's heady stuff for the second- and third-oldest of 14 children who grew up working on the family farm in Tintah, Minn. As kids they converted horse buggies into go carts, made toys out of wagon wheels, and fixed farm equipment and "all the things we busted up," Cyril chuckled.

"We didn't have much education," Cyril said.

"Nope. Once we got to the eighth grade, that was it," Louis said. "We had to help out on the farm."

"That's why I say that the will of God works for everybody. You didn't need much education in those days," Cyril said. "Everybody has a gift."

Their talents were used during World War II. Cyril served as a Navy cook in the Pacific. Louis became a field mechanic for the Army in 1945, fixing jeeps, airplanes and trucks at a base in the Philippines. Then his unit was shipped out. Mission: Invade Japan. But the war ended with Japan's surrender shortly after America dropped two atomic bombs.

The war over, the brothers headed back to northwestern Minnesota. Cyril went to work for a foundry. Louis, by then a husband and father to the first of his 10 children, worked for a couple of years in a foundry before opening his own blacksmith shop in Rothsay in 1947.

Always tinkering, Louis saw the snow thrower a friend's company produced and just didn't think much of the design, which placed the thrower on the back of the tractor. He tinkered in his shop, designed and built a front-end blower, the rights for which he sold to Farmhand Co. in 1948. He developed a walk-behind blower in 1949.

Moved to Gwinner

Once Melroe was sold on their self-propelled loader, the Keller brothers moved in fall 1958 to Gwinner, N.D., population 250.

Louis joined the engineering team, helped improved the design of the loader and worked on several attachments. Cyril, who spent the next 26 years with Melroe/ Bobcat, took to sales and hit the road.

"They wanted someone to get on the road and work with dealers, and I started right away talking to different turkey barns and cattle and hog barns, construction yards, foundries and ship-unloading companies. It was nonstop," Cy recalled.

His first order came from a fertilizing company outside Sioux City, Iowa. It bought two. Down the road, a foundry bought one. A turkey farmer bought another. By the end of the week in 1959, six machines were sold for around $1,400 each -- about $10,350 each in inflation-adjusted 2008 dollars.

"Roger [Melroe] was very pleased," said Cy, who later headed training for the company and marched hundreds of workers through what is now dubbed Bobcat Bootcamp.

After leaving Bobcat, Louis one-upped himself by creating an even smaller "Mini Bob" machine that spanned just 3 feet with four-wheel drive.

Melroe executive Roger Melroe sneaked Louis Keller's newest product into a dealer convention in Phoenix, much to the surprise of the other Melroe brothers, who had previously rejected the idea.

"Some 925 orders came in one night," Louis said. "All the dealers saw it and flocked. The brothers said: 'What in the world is going on?' They called me and said you have to come [back to get this into production]. I was king of the hill."

Dee DePass • 612-673-7725