FISH CAMP -- Why stop at 26.2 miles?

Especially at 5,000 feet elevation, where the air is fresh and cool and the dirt feels soft underfoot. And the scenery is top notch.

At the annual Shadow of the Giants 50k, there are vistas, creek crossings and trees so immense some runners stop dead in their tracks -- even during the middle of the race.

"I probably lost 2 or 3 minutes just looking at trees," says Lon Freeman of Contra Costa County.

Finishing times are important, but not nearly as much as the experience. For some, just finishing is good enough. There's no better way to explain the rapid growth of ultramarathons, typically races of at least 50 kilometers (31 miles) but sometimes 100 miles or longer.

In 2011, 52,000 runners in the U.S. completed ultra-length races, UltraRunner magazine reported in its March issue. That might not sound like a lot, but it's more than triple the number (15,500) who finished ultras in 1998 and 18 times more than in 1980 (2,890).

Aaron Samansky, owner of Sierra Running Company in north Fresno, attributes the popularity surge to the fact that more novice runners start out doing longer distances. Instead of 5k and 10k races that were en vogue 10 years ago, he says half marathons are the current rage. (Two best-selling books, Dean Karnazes' "Ultramarathon Man" and "Born to Run" by Christopher McDougall, also spiked interest.)

After you've run 13.1 miles, marathons become the logical next step. And after that, ultras. Which, rather than pavement, are usually on trails and fire roads.

"It's a different kind of running," Samansky says. "People who do marathons complain about being beat up from the road. Running on a trail forces you to slow down a little and enjoy the scenery. That appeals to a lot of runners."

It certainly appeals to the 96 who lined up at Green Meadows Outdoor School bright and early Saturday morning for the 23rd edition of the Shadow of the Giants 50k. While not long by ultra standards -- the 50k course comes up closer to 29 miles than 31 -- there's also nearly 6,000 feet of climbing, at elevation, to ratchet up the difficulty.

By appearances, none of these folks look like they just rolled out of bed and decided to run 50k. Speaking of ks, Special K would hate this group because there isn't an inch of fat to be pinched. Skin looks shrink-wrapped. Veins bulge. Calves pop. Thighs appear straight out of a human anatomy textbook.

Front and center, bare-chested and wearing green forearm sleeves, stands Oswaldo Lopez. Next month the 40-year-old Madera man will defend his title at the 135-mile Badwater Ultramarathon, billed as the world's toughest footrace. Next to Lopez stands 23-year-old Maria Rivera of Visalia, who over the last year has taken the local running scene by storm.

There's a large turnout from Southern California, headed by 41-year-old Michelle Barton of Laguna Nigel. With her glowing smile and long, flowing red hair, Barton doesn't look like one of the country's most-decorated ultra runners. But she is.

And who's that loud guy with the white beard and British-by-way-of-Australia accent? It's Barry "Baz" Hawley, a former competitive runner who founded the Shadow of the Giants in 1989 and has been organizing ultras since 1984.

Hawley plotted the Shadow of the Giants 50K course when he owned a B&B in Fish Camp. It's changed a little over the years, mainly due to road conditions, weather and forest service regulations, but always includes the Nelder Grove of giant sequoias.