The throaty rumble from hundreds of Harley-Davidson motorcycles filled Downtown St. Joseph Wednesday, previewing a ride once popular in the early 1860s.

Among the ride’s participants is Willie Davidson, grandson of one of the company’s original founders and a leader on the design team. History has proven to be a suitable guidepost in planning Harley-Davidson rallies. In 2002, a rally traced the path Lewis and Clark took to reach the Pacific Northwest.

The Harley Owners Group (H.O.G.) — Harley-Davidson’s official ride club — plans to head out today over the same mail-laden path that Pony Express riders took on horseback. Joe Dowd, Harley-Davidson’s manager for event strategy and execution marketing, said roughly 500 motorcyclists are participating in the ride.

Mr. Davidson said the company’s pre-arranged rallies provide historic facts to the participating motorcyclists.

“It’s a fun ride, but it’s also educational,” he said.

The Pony Express Ride should be no less informative.

“I am just fascinated by the history in this part of the country,” Mr. Davidson said. “Your (Pony Express) museum does a fine job of explaining that.”

According to the company’s Web site, the owners group sponsors stationary and touring rallies throughout the United States. The group’s mission, purpose and philosophy are simply to ride and have fun as part of one big, happy family.

“We do different rides every year,” Mr. Dowd said. “We hardly ever repeat the same ride.”

Previous rides have included a trek from South Padre Island in Texas to the International Peace Garden on the U.S.-Canadian border, and the famed Route 66.

The group’s members spent the day ahead of their St. Joseph departure enjoying group photos at the Pony Express Statue at Ninth Street and Frederick Avenue, and touring the city’s museums.

“The city of St. Joseph has been great,” Mr. Dowd said. He also praised the St. Joseph Convention & Visitors Bureau for assisting the group.

North Platte, Neb., is the tour’s next scheduled stop. “We’ll hit all the Pony Express icons,” Mr. Dowd said.

The owners group boasts of more than 1 million members who hail from 46 states and overseas locales such as Hong Kong, Japan, Germany, and Australia.

Gary Chilcote, director of the Patee House Museum and Jesse James Home, said he began heaping hospitality upon some of the motorcyclists Tuesday. Many members had decided to return for a second look at the museums, he added.

“This is a big impact for us,” he said. “They’re nice people. It’s a good group.”

Mr. Chilcote said he plans to head to Kearney, Neb., for a National Pony Express Association meeting, where he expects to encounter the motorcyclists once more.

As the company’s senior vice president for design, Mr. Davidson works with a team of 20 people in helping create tomorrow’s motorcycles. He’s been with Harley-Davidson for 46 years, helping with the latest trends but also promoting the company whenever he’s able to get on the highway.

“We work constantly on new models,” he said. “We’re out seven or eight years.”

Despite weak sales that saddled his industry, Mr. Davidson remains optimistic of an eventual rebound. Harley-Davidson was forced to make reductions in employees, production and other areas to cope with the sales downturn.

“We see some light in the tunnel,” he said of the company’s future. “There’s some glimmer of hope ... We’re watching very close.”

A Fortune 500 company such as Harley-Davidson must be cautious in marketing discretionary products such as motorcycles, Mr. Davidson said.

The H.O.G. Pony Express Ride is set to conclude next week in Sacramento, Calif. — the mail route’s original western terminus.

Ray Scherer can be reached at rscherer@npgco.com.