The Lucas Oil Pro Motocross Championship is the premier motocross championship in the U.S. Sanctioned by AMA Pro Racing, the series features the fastest outdoor motocross racers competing at some of the toughest tracks across the country.

The 12-round championship spans the country, and like Supercross, there are two classes based on engine displacement. The premier class, AMA 450MX, features 450cc motorcycles, while the support class for up-and-coming riders in the sport, AMA 250MX, features 250cc machines.

Pro Motocross is a one-day event with two 30-minute-plus-two-lap motos for each class. An overall winner is declared for the event based on scores from each moto, with tiebreakers going to the best result from the second moto. The tally of points from every moto decides who will be crowned champion. Held during the summer no matter the weather conditions, each track presents a mixture of jumps, hills, corners, and whoops to put the riders’ fitness to the test.

With a history spanning 50 years, the Pro Motocross championship has produced many of motorcycle racing’s biggest stars. In the early days, European riders dominated the sport they invented, but it didn’t take long for the American riders to catch on. Legends like Bob Hannah, Marty Smith, and Jimmy Weinert helped pave the way for future generations of motocross stars in the U.S.

During the 1980s, Broc Glover, Rick Johnson, Jeff Ward, Johnny O’Mara, and David Bailey raised the bar in the sport. That torch was passed on to the modern era’s stars: Damon Bradshaw, Jeremy McGrath, James Stewart, and Ricky Carmichael.