The rough trails and steep hills of Comite River Park were built to test mountain bikers and their two-wheeled machines.

But Cole Rankin takes them on with just one wheel.

A unicyclist for the past four years, the 16-year-old Central High senior loves to test himself.

“I like that it’s hard,” Rankin says as he prepares for an evening ride, assembling shin guards and his lightweight bike helmet. “You can pretty much find a challenge everywhere. You can go in the street and every little curb is an obstacle. Or you can go to the trails where they are built to be obstacles. It’s a whole different experience.”

Off-road unicycling has attracted a handful of adventurous riders to the trails. Rankin is among the most talented, says fellow unicyclist and friend Austin Parker, a 17-year-old Denham Springs High student.

“You put him on anything with wheels and he can do it,” Parker says.

Thin and moving fluidly like a gymnast, Rankin mounts his fat-tired unicycle as easily as a die-hard Tigers fan might kick back in a recliner. To warm up, he works on tricks in the trail parking lot, spinning the unicycle beneath him and flipping the seat backward and forward, then pedaling with just one foot.

He hops on to a picnic table bench, stumbling off balance once, then trying again. On his second try he bounces from the pavement to the bench, then to the tabletop, where he pedals a couple of revolutions and rolls to the ground below.

Over the past four years Rankin has developed this talent by watching YouTube videos online and riding around his neighborhood in Central.

“A lot of practice,” he says with a confident grin. “You just do it and do it and do it.”

When he was 12, Rankin saw video of a unicyclist on the famously difficult mountain bike trails of Vancouver, British Columbia. Riding motorcycles since he was 6, Rankin was familiar with off-road riding, and unicycling on trails became a new infatuation.

He bought his first unicycle off eBay and learned to ride in his driveway in about three days. Mounting the unicycle without holding onto a pole or a wall took about a week.

“A lot it is, you have to be a really determined person and really want it,” Rankin says. “If you’re just like, ‘Yeah, I’ll try this,’ and you give up after a couple of days, you’re not going to get it.”

The cheap eBay unicycle didn’t last long, so he upgraded to a better one. Then, last Christmas he got a burly machine used for the form of riding called “trials” — a competitive sport that tests technical skills like hopping up rocks or riding on a rail. The trials unicycle has a fat, small wheel. It isn’t ideal for riding miles in the dirt — mountain unicycles have larger wheels for better momentum — but he can complete the 6-mile Comite trail in 90 minutes.

On the ribbon of narrow trails at BREC’s Comite River Park, Rankin rolls along, his arms stretched out for balance, his eyes locked a few feet ahead.

However, his brain works constantly to make judgments about tree roots and elevation. A bad angle can quickly stop his 20-inch wheel.

“Riding trails you’ve got to read every root that you see on the ground, every little hill,” Rankin says. “Nothing comes quick.”

Because unicycling requires a significant time commitment, Rankin and Parker don’t think the sport they love will ever be as popular as mountain biking.

“Your average person might brush it off like we used to and say that’s stupid,” Parker says. “But if you reach the right people it might explode.”

A few miles into the trail, a steep hill presents a challenge most bicyclists will never know.

A short climb nicknamed The Wall saps the momentum from Rankin. He can’t shift gears and power up, so he rides as far as possible. When the hill becomes vertical for a couple of feet, he pivots sideways and hops three times to the top.

Rolling free of The Wall’s peak, Rankin smiles, then balances and rolls back and forth to assess the next downhill.

The challenges never end — just how Rankin likes it.