Spenser Robert

The Big Business Of Dirt In American Supercross

The madness behind building supercross tracks


here’s a parking lot between Angel Stadium and California State Route 57. Most of the year it’s elevated on 7,000 cubic yards of soil, but between Christmas and New Year’s, workers from Dirt Wurx USA demolish the 45,000-square-foot expanse, mine the earth below, and dump it onto the Anaheim Angels playing field to build two supercross and five monster-truck courses. And once Feld Entertainment, the promoters behind Monster Energy Supercross and Monster Jam, are through with the venue, those same workers put it all back, right down to the field’s green grass and the lot’s white painted lines. They do this because dirt is worth exactly nothing until you need it moved. In California, it’s cheaper to build and destroy a parking lot each year than it is to store or haul the soil from elsewhere. It reduces the number of dump-truck meter hours, allows the crew to use larger-capacity off-road trucks, and eliminates the monthly expense of stockpiling dirt in a nearby leased lot, which Feld once did. Rich Winkler founded Dirt Wurx USA in 1992. He was a curious kid in the 1970s and excited about the process of making supercross tracks, especially because they took place in sporting cathedrals like the Los Angeles Coliseum where the playing field was considered sacred ground.

Angel stadium supercross dirt track
Work starts just after Christmas, giving Dirt Wurx a little extra time to build Monster Energy Supercross round one in Angel Stadium. In 2018, the dirt was filtered. The source parking lot can be seen in the distance.Spenser Robert

“This was new territory, how you could put dirt into a place where it’s not supposed to be and not destroy the place,” Winkler says from his Monroe, New York, office.

Now 60, he jokingly calls himself a dinosaur. He’s owned 40 motorcycles and once raced professionally. He was 22 in the early 1980s when he started working with a supercross promoter, but after five years he saw a lucrative opportunity, not in the dirt, but in plywood.

Unless a stadium floor could be stripped to bare concrete, workers had to lay down a layer of thick plastic, then two layers of plywood at a total of 6,500 sheets. Winkler borrowed $60,000 (more than $140,000 in today’s dollars) and became the official plywood supplier for dirt events in stadiums. He made his money back, but the logistics of moving the sheets between cities was more difficult than building courses.

Clearing dirt for supercross track
Cleaning the dirt.Spenser Robert

“It was a clown act,” he says.

The venture lasted two years before he dumped it and focused on course construction. It took some time, but in 1998, Dirt Wurx became the exclusive supercross series track builder, and it has been ever since. For 20 years “Wink” and his team have watched the equipment and athletes improve.

Dirt is worth exactly nothing until you need it moved.

Maybe that's why Dirt Wurx crewmembers like Randy Mennenga just smiled when everyone raved about the "new" dirt at the Monster Energy Supercross course at Angel Stadium. There was nothing new about it or the steps that went into making the track. Mennenga, who calls himself a professional dirt farmer, stood in the first corner and watched bikes take on and tear up the masterpiece he and his fellow workers built over a 90-hour workweek.

destroying parking lot for supercross track
Destroying the parking lot.Spenser Robert

This was the first of 16 courses Dirt Wurx would construct between January and early May. If Mennenga, 44, was nervous, he didn’t show it. He’s been doing this since 2002. Switching between hands in pockets and arms folded, he looked tired but alert. His goatee was overgrown and graying. He was neither shy nor chatty. His expressionless face would be hell at a poker table.

The course was finished the previous evening, that parking lot full of dirt shaped, scraped, and stacked to form a 2,100-foot-long track filled with jumps so steep, they’re difficult to climb on foot. The Dirt Wurx team couldn’t do maintenance until 2:35 p.m. when the first set of qualifying sessions concluded. Mennenga didn’t need to be there at 9 a.m., but he was anyway, ready for feedback.

“If we didn’t take so much pride in what we do, we could just leave the track the way it is,” Mennenga says.

dirt worx employee
Dirt Wurx workers maintain the course.Spenser Robert

Current riders often come to the Dirt Wurx crew with requests. It’s up to Mennenga and his team to determine if the task is something the track actually needs or if the change will just make that rider’s life easier. When the first window for course maintenance opened, three skid-steer loaders descended on the track. They had exactly 35 minutes to make any adjustments, this after two and a half hours of qualifying sessions, each with 20 to 30 bikes.

I bent and grabbed a handful of dirt from a spare pile in the infield. My hand sunk in like I’d plunged it into a bulk barrel of dry beans. Milk chocolate in color, free of rocks and debris, and neither too dry nor too wet, it was pure, perfect soil. The dirt was soft, but with the right amount of water and pressure, it could be packed tight enough to withstand 12 hours of pounding from scores of 240-pound four-stroke motorcycles, all running freshly edged, knobby tires.

Meanwhile, outside the stadium, two loaders were busy dumping soil into a Powerscreen Chieftain 1400, a multiprocess industrial sifter that weeds out garbage, rocks, and other debris. After passing through several filters, a conveyor carried the remains up a belt and dropped them into a pile. Watching the material go into the screener, it was easy to see why people mistook it for new; this dirt went to the laundromat.

Randy Mennenga
A warmer shirt, a sack lunch, and a bulldozer are all Randy Mennenga needs to get him through the load-out portion of a weekend.Spenser Robert

Eli Tomac is Kawasaki's number one rider, twice a runner-up in this series, with nine victories in 2017. He has dabbled in maintaining his own track in Colorado. He laughed about not being able to build a set of whoop-de-dos, the very obstacle he's strongest at riding.

“Track building is an art,” Tomac says. “You literally have to have good touch to operate that equipment and make the jump faces and angles. It takes patience, and these guys have to do it all in a hurry.”

The skills needed to craft the whoops can’t be learned from a background in excavation or landscaping, only by building courses. I watched the blade of the bulldozer rise and fall as it pushed dirt forward and scraped it back to fill in ruts and alter the pitch of the jumps. It looked as effortless as Tomac floating over the finish line.

That evening, the stadium filled with 45,050 spectators, and the racing went live on TV. The maintenance windows dwindled to nine-minute sessions. The Dirt Wurx crew was unfazed. They executed their plan, parked their machines, and waited for their next session. In between, they watched racing or heckled each other via group text.

parking lot
When the events are over, the dirt goes back to being the foundation of a parking lot.Spenser Robert

“If you’re not a supercross fan, this is just a shitty job with a lot of hours,” Winkler says of the grind, which demands 16 of the first 18 Saturdays every year. Blueprinting for the following year’s courses begins in June.

When the race was over, the crew flattened the course and removed 30 percent of the dirt for monster trucks the following weekend. By early afternoon Monday, the crew would be in Houston at NRG Stadium, home of the Texans, directing the dump trucks bringing in dirt from an off-site location. There wouldn’t be as many compliments with Houston’s dirt; it wouldn’t get screened. That’s another part of the job. There’s criticism from riders and teams for build quality and how well dirt holds up. On the latter, earth is different from city to city because each region has its own geological makeup. The dirt is going to be moist and soft in Seattle.

In Minneapolis, it could be frozen.

Mennenga is not daunted. He keeps grinding. Before he climbed into his Caterpillar D4K2 bulldozer, he put on a blaze orange hoodie. A friend was waiting in the tunnel, cradling a brown-bag lunch in one arm and an 11-year-old Jack Russell terrier, Spanky, in the other. Spanky assumed a pose of superiority when Mennenga placed him on the floorboard of the dozer. Clearly, he’d done this before. As the machine rumbled out of the tunnel and onto the remains of the course, the dog watched proudly through the window. The sounds of soil being moved were a symphony of metal on metal, metal on earth, and backup sirens. For the dirt farmers on the supercross tour, it’s the soundtrack of their lives.