Motorcyclists arrived in Audrain County from all four directions last weekend, although few if any people on the roads recognized an increase in traffic.

Some 300 adventure riders took part in the annual Adventure Palooza, arriving at a farm just north of Mexico after navigating courses running 400 to 600 miles. Instead of cruising along smooth stretches of asphalt, they traveled diabolical routes laid out by Dale McIntosh and John Wilbers.

The tracks take riders through all manner of potential trouble -- loose gravel, sand, rutted ledges studded with ominous rocks, trails broken by fast running streams. Each year 80 to 90 percent of the ride covers some form of natural terrain.

McIntosh and Wilburs introduced Adventure Palooza in 2017 as a way to raise funds to benefit the Wounded Warriors Project, as well as to create two scholarships to assist local students. Since then it has grown to become one of the state's largest adventure riding events.

The sport is not new. Riders have gone off road and overland, carting camping gear and challenging their self reliance against nature for years. The American Motorcycle Association promotes a national adventure riding series. Manufacturers build bike models specifically for the purpose.

But McIntosh and Wilburs created something beyond the norm of what is already beyond the normal of motorcycle riding.

"This is where a game became involved," McIntosh said. "Riders compete in a game that tests their skill, ingenuity and cleverness."

The pair research and lay out four courses that begin on a Missouri border and careen toward the Wilbers' farm, crossing as McIntosh puts it, "some of the toughest terrain the state of Missouri can throw at them." Along the way they must find GPS locations set out by the two, find hidden washers that are numbered and answer trivia or riddles.

When it's all over, the riders spend a day relaxing in Audrain County, sharing tales of their ride.

If the ride sounds like a lot of effort, McIntosh and Wilburs have already put in much more by the time Adventure Palooza starts. In a month they will begin planning and plotting the courses for 2022's ride. They take their bikes out and test different routes and search out likely waypoints for the game.

By the time the two settle on the courses, each have ridden some 6,000 miles, including every mile of the approved courses.

Participants pay a fee for all of this, which helps toward the scholarships and contribution. But they also receive dinner, live music, a t-shirt and more at the destination.

"The growth of Adventure Palooza in just five years is thanks to the help of generous donations," McIntosh said.

Gateway BMW, a motorcycle dealership in St. Louis, is one of the principal supporters. KLIM, Giant Loop, Rocky Mountain ATV, The Helmet Hook and Hadens Motorsport all help out. And there are a number of anonymous donors.