Who could have known that riding a bike could be so difficult? The trail was 12 inches wide and keeping the front tire of the mountain bike on it had become an exercise in futility. The climb was steep. Roots abounded and trees leaned in. Chest heaved, legs burned, arms ached.

Perspiration was exhilaration. Who could have known?

A few minutes later, the second most strenuous ascent of Brown County State Park’s rugged mountain biking trails was behind us. We were at about 950 feet, one of the park’s high points. Bikes were parked in a clearing not far from Aynes House. Water bottles were out. It was a sweet June evening in the deep woods. Birds chirped. The breeze was a soft rush in the leaves overhead. The conversation was warm.

“People who want to go to Florida are crazy,” Jonathan Juillerat offered. “Get out in the woods.”

Juillerat manages Nebo Ridge Bicycles in Carmel. He serves as an officer of the Hoosier Mountain Bike Association and is a director at large of the International Mountain Bicycling Association. He also is a huge advocate of mountain biking in general and the trails at Brown County State Park in particular.

With 12 miles of trails traversing steep ridges and tumbling into deep ravines and another 10 miles under construction, Juillerat sees Brown County becoming one of the top mountain biking destinations in the Midwest. The rugged country, unspoiled woods and high-quality trails draw riders from Indianapolis, Cincinnati and Louisville, Ky.

He sees the day that Brown County’s trails are linked to nearby Hoosier National Forest, where the Nebo Ridge and Hickory Ridge trails extend about 55 miles.

“That’s a lot of miles in a small area and I personally think the people who will like this the most are people from around Chicago,” Juillerat said. “You can bring your Aunt Millie and drop her in Nashville and go mountain biking. Your wife can go shopping or riding.”

HMBA rates the Aynes Loop and Hesitation Point Trail, parts of which we biked that evening, as “intermediate.” The park ranks them “difficult.”

Depends upon your perspective.

Juillerat and his riding partner, Ron Lewis, manager of Rusted Moon Outfitters in Broad Ripple, are accomplished mountain bikers who don’t have two pounds of body fat between them. They’re atop Hesitation Point twice a week to see the sun set and it’s exhilarating just watching them power up ridges, bomb descents, skim creek beds and bunny-hop logs.

“Borderline reckless,” as Lewis put it.

The pace is more moderate, but the ride no less fun for the novice. Heart rates run just as high racing downhill as struggling uphill. Cares have no place on a mountain bike in the forest.

Brown County’s system also includes the North Gate Trail and the North Tower Loop. Both are rated “moderate.” Juillerat’s 5-year-old son, Ian, has ridden the North Tower Loop and portions of the other trails. There is something for everyone.

Juillerat and Lewis would seem to have better things to do than to shepherd a rookie through a rough ride, but they were unfailingly patient, helpful, instructive. Look as far down the trail as you can see, urged Juillerat. Use your gears. Carry some momentum through tough spots, counseled Lewis; it makes them less tough. And, of course, fall into the hill, not down it.

I did both.

At one point, we passed a rider walking his bike out of the woods.

“Got a flat? Need help?” asked Lewis. Juillerat made the same inquiries as the rider passed him.

It’s the mountain bikers’ creed. Give aid. Of course, so is this: Be prepared. Carry an extra tube or patch materials and tools. The rider with the broken bike had neither and didn’t seem to want to admit it.

“You always want to ride out,” Lewis said. “It’s a point of pride.”

Of course, that sometimes is easier than others.

Juillerat and Lewis recalled a Brown County ride of a couple of years ago. Juillerat snapped off his derailleur, the device that shifts the chain from one sprocket to another, one gear to another. His 27-speed bike was reduced to a one-speed bike. Then, on his third flat of the day, the pump broke.

They’re still laughing about it. That’s the point: It’s all good.

The best ride “is the last one,” Lewis said, “and the next one.”

Take it on faith.

Your intrepid reporter finished with a bruised left shoulder overlaid with a grid of angry scrapes. Blood trickled from my left ankle, left elbow and right knee.

The ride was exhausting and exhilarating. So is the memory.

I since have borrowed a bike and taken another, less rigorous, ride. I’ve surfed the Internet. I’m buying a mountain bike.