It's just before dawn at the Duluth parking lot of the North Shore State Trail. The cool nip of fall sharpens the air as a few cars pull in and their occupants begin bustling about. In the dim light, two bright objects stand out: last night's nearly full moon, which is just now setting over the boggy western horizon, and the headlamp of Jeremy Kershaw, founder and director of the Heck of the North 102-mile bicycle race, which will take place today.

At a folding table, Kershaw's lamp illuminates a clipboard with his list of 150 registered riders. As early birds start to arrive, he ticks them off one by one. His wife, Avesa Rockwell, is beside him, handing out waivers, race numbers, and the cue cards that will direct the cyclists where to turn on the unmarked route.

Riders come from Minnesota and neighboring states to ride this race, which is part of a proliferating form of bike competition: gravel-road racing. Sometimes known as gravel grinders, these events exist somewhere between the rough and tumble of mountain biking and the smooth glide of road riding. They come in many forms and sizes, but 100 miles is a common distance, and many of them share a do-it-yourself ethic and a strong sense of community. In an era when big-time bicycle racing has been tainted by doping and plastered with advertising, these earthy events, many of them free or low-cost with no big prize money, are taking biking back to its roots.

The Heck of the North's name is a sly twist on a legendary French bike race, the Paris-Roubaix, nicknamed the Hell of the North. "I wanted to do a tongue-in-cheek name playing off of the biggest one-day event in the cycling world," says Kershaw. "It's a race run outside of Paris, largely over these sections of old cobblestone farming roads."

Minnesota has few cobblestones, but it's got plenty of gravel. The Heck of the North takes full advantage of the many rugged roads northeast of Duluth. The 102-mile loop is 75 percent gravel, 20 percent pavement, and 5 percent trails and paths.

The race is run at a time in the fall when, if a visitor is lucky, the deciduous trees are exploding with color. And this year, 2012, the riders are very lucky.

At the race check-in, the vibe seems more flea market or folk festival than athletic contest. A few riders have sleek team outfits, but many look ready for a backyard barbecue. As darkness fades and the day brightens, many of the bikers ingest energy-rich breakfast foods and gulp performance-enhancing doses of strong coffee.

The riders must be self-supported, carrying gear and snacks for the day, save for a halfway checkpoint where their lunch bags have been transported by volunteers. The Heck of the North is a truly remote race, where "there's not even a gas station to buy a Snickers bar," says Kershaw.

Dave Sears, who organizes bike races in North Dakota, makes final adjustments to his rig. He's come to "see how these guys do it," he says.

Garrick Yoong, of Minneapolis, is outfitting a vintage steel-frame bike with canvas bags. He has ridden every Heck since the first one in 2009, except for 2011, when he was being treated for cancer. He's glad to be back on the saddle. "I'm a pretty slow rider," he says. "For me it's not a race."

Marcus Bush, of Minneapolis, is wearing a Lycra outfit and attending to a skinny-tired road bike. He says this is his first gravel race, and he's keen to try it. Has he trained much? "I wish," he demurs. He adds that the biggest challenge may be staying on course.

Tim Ek, of Duluth, has placed third and fifth in past iterations of this event. "This race represents the best Minnesota has to offer," he says, citing the Heck's remote feel and north-woods scenery.

The majority of the riders are men, but the number of female riders has risen every year, to 15 this year. Among them is Monika Sattler, a German-born University of Minnesota grad student with a background in international adventure racing and road-bike contests.

Not everyone is racing for a win, explains Kershaw, but the Heck is a race nonetheless, whether it's against the clock or one's own energy reserves.

"I'm very fortunate to have this group of riders," Kershaw says. "They're a really great group of people to be around, to ride with, to share an adventure with."

With the quiet but powerful hum of hundreds of tires, the riders hit a rolling start just after 8 a.m. They head straight east toward a Lake Superior sunrise, as a great blue heron takes wing close overhead. The next few miles take them through a zigzag of paved two-lane roads toward the northeast, where the heart of the gravel lies past a "Pavement Ends" sign.

A little more than an hour into the race, Marcus Bush, the fellow who implies he's undertrained, has a significant lead. He doesn't even look winded as he breezes along Rossini Road, a famously rough stretch of gravel.

Because the Heck of the North follows a relatively flat inland route for most of its length, the early part of the race typically doesn't shuffle the riders' order too much. Soon after the 20-mile point, when the route suddenly disappears into the brush on a section of the North Shore State Trail, things often get interesting. But in this dry fall, the portion that can be muddy is barely wet, and the trail does nothing to break Bush's lead.

Lunch is a luxury that the most competitive riders don't allow themselves. They make a required check-in stop at the halfway point, then gulp some energy-gel packets and keep pushing. So Bush and the other front-runners are long gone when more casual riders show up at the lunch drop.

It's a scene of hastily indulged, well-earned comforts. Some riders tend skin scrapes and wash off mud. All scarf down food like it's the best thing they've ever eaten. One rider, not yet sated from eating an entire tin of sardines, tips the can up to slurp every omega-3-laden drop of oil.

Back on the road, Marcus Bush has vanished from the lead and, by all appearances, from the race. A pack of four riders now battles for the lead.

"We were being chased by an angry pack of Duluth guys for a good 30 to 40 miles," Ted Loosen, of Minneapolis, later recalls. "I don't think we ever got more than two or three minutes ahead of them, and we were going as hard as we could."

In the contest's final miles, another game changer shakes up the race. Because the Heck is a small race, roads remain open to motor vehicles. Now a traffic accident has shut down Lester River Road just as the leaders approach. A suspected drunk driver has careened into the ditch, knocked down a power pole, and fled into the woods. With the live power line on the road, firefighters stop all traffic, including racers.

Loosen and his fellow leaders, all out-of-towners, don't know the best route around the closure. But the Duluth riders catch up and guide them on an impromptu detour and then, in the final stretch of the race, give them a head start toward the finish line. Loosen finishes in first place.

"It was a very gentlemanly thing to do, a very nice gesture on their part—not something you see in normal bike racing, let's put it that way," says Loosen. "That's one of the things that makes these gravel races unique. They're kind of a throwback in some regards. A little more chivalry."

After the downed line is fixed and the road reopened, many slower-paced bikers roll through. At the race finish, they swap stories about other obstacles. One rider's bike frame broke in half, sending him to the gravel in a heap. Another sustained a stitch-worthy cut on his hip from grazing a metal sign. Flat tires, brake malfunctions, and moments of existential angst all figure into the chatter.

Marcus Bush turns up at the finish line in mid-pack with a remarkable story: He went the wrong way at the halfway checkpoint, plunging deep into the woods on a wild goose chase that cost him his huge lead and then some. He contends a volunteer misdirected him, a point that Kershaw concedes while noting that riders are ultimately responsible for finding their own way.

Tim Ek is irked about the traffic incident. "At this point, the race is null and void," he fumes. "People were coming in from all directions."

Others are far less competitive and more sanguine. Dave Sears rolls in late in the day, after enjoying a ride along scenic Highway 61. "I missed the halfway cutoff, so I took the North Shore route instead," he says. "As much as I would have liked to complete the race, I had a great time anyway."

Sattler, the top women's finisher, has no doubt she'll be back. "It was my favorite race of the year," she says.

Amid the hubbub, volunteer Rick Mangan, of Grand Forks, sings the praises of the Heck's setting on public roads and public lands. He and his daughter Gabrielle helped out at the race site for the day while his wife went hiking on the nearby Superior Hiking Trail.

"We're all using the resources, we're just using them in different ways," says Mangan. "There's room for all of us to play."

Late in the afternoon, two of the race's older riders roll in, red-cheeked and weary. "What a day out there!" one of them says. "Flat tires, everything. It was a heck of a ride."