Along with sweltering heat, the onset of June brought the Lehigh Valley's first Tough Mudder event to David Jaindl's Raven Valley Farm, an expanse of rolling hills in Heidelberg and Lowhill townships. Jaindl, businessman and owner of JaindlAG, entered into an agreement with Tough Mudder to lease the land for the event.

Carved out of the fields of wheat were an array of bizarre-looking structures, connected by a pathway that snaked through the 400-acre site for a distance of at least 10 miles.

A line of runners could be seen from Route 309 winding its way over the hills. A fleet of yellow buses plied the rural roads, disgorging scores of well-toned bodies in sleek outfits at the top of a hill.

The mood was upbeat as hundreds of runners and spectators milled about a large area of white tents, rows of portable toilets and a high metal platform emblazoned with names and logos of various sponsors.

Rock music blared from a speaker. Many participants had their numbers stamped on their foreheads, but in the early morning heat they were already sweating them off.

Rachel Donatiello arrived from Lansdale with friends Beth and Ben Reasoner and five other teammates. The slight young woman was asked by this reporter if she was nervous.

"A little," she replied with a grin.

Billed as "the premier obstacle course series in the world," the Tough Mudder challenge is a 3-year-old phenomenon designed by British Special Forces to test "all-around strength, stamina, mental grit and camaraderie."

Held in several countries and many locations in the U.S., the course has drawn more than 700,000 participants and raised $5 million for the Wounded Warrior Project.

Obstacles range from the merely challenging to the horrific. Some involve physical challenges such as scaling walls and ladders, hanging on ropes, running through mud and climbing mountains of hay bales.

Others involve crawling through ice while being shocked from above with 10,000 volts of electricity, crawling through underground trenches or swimming under barrels through frigid water.

A new wave of runners assembled at the start gate every 20 minutes. Dressed for action and the hot weather, most Mudders turned out in functional outfits of shorts, T-shirts and tanks.

Some wore shirts with team names like "Filthy Animals," while some had company shirts. A few teams carried a flag, which they deftly passed from one member to another while traversing obstacles.

One team of guys sported purple shirts, pink shorts and tiaras.

Once assembled, each wave was rallied by a promoter with a loudspeaker.

First came instructions. Runners were warned of the effects of the heat.

"Hydrate," said the announcer. "Do it now. Don't wait until you're thirsty … then it's too late. If you're not sweating, you need to get off the course and hydrate, take a break and cool down.

"If you can't swim, don't jump in the water! When you're going into the water, be aware of everyone who goes in with you, and make sure everyone comes out."

Lastly, he reminded everyone, "You're not just here to complete a course; you're here for a wonderful project: The Wounded Warrior Project."

The group was then asked to face the flag for the nationalanthem, followed by 10 seconds of silence. Then everyone was led in a cheer of "Hoorah!" three times.

Next, the runners had to raise their right hands and repeat:

"I pledge that I understand Tough Mudder is not a race but a challenge. I put teamwork and camaraderie before my course time. I do not whine. I help my fellow Mudders complete the course. I overcome all fears."

Those who were veterans or in the military were asked to stand up, and many in the crowd stood.

Charging over the first hill, the runners soon arrived at their first obstacle, the Kiss of Mud, where they slid through the muck on their bellies under a net of barbed wire.

Here they were just getting warmed up. About halfway through they encountered Balls to the Wall, a wooden wall that had to be scaled by means of thin planks, then descended by ropes on the other side. People shouted directions to those behind them.

"Swing your leg over … grab tight to the rope … look for the knots!"

Spectators could view about half the obstacles from the spectator track, which stays fairly close to the base area.

Bob Metz, from Allentown, was impressed.

"I went through basic training at Fort Knox, and that was a piece of cake compared to this," he said.

Crystal LaFrance from Annville was there to watch family members do the course. Her husband had been training for it since January.

"He grew a beard for the event," she said, "and he won't shave it off till it's over."

Easily viewed from the finish line was the course's final obstacle, Electroshock Therapy. The runners ran in the mud through a forest of dangling wires, some yelping as they received shocks. Mostly, though, their faces showed relief to be at the finish line.

Matt Pitz of Downington was one of the first few to finish on Saturday. A second-time Mudder, he said he had trained hard for the course.

"It's not easy," he said. "It was a lot harder than I remembered from last year. The first time I got shocked it really startled me."

Diana and Steve Marsteller returned to the Lehigh Valley from Baltimore, Md. for the event. It was the second time for her; the third for him.

"It gets a little easier each time," said Diana. "It's fun to do it with new people, because you can help them."

After the first time she didn't want to do it again, but was talked into it, she said, although she almost backed out a few days before.

"There are new obstacles each time, so you never know what to expect," Steve said, adding The Electric Eel and the Artic Enema were the worst. "But it's always fun. And they do a lot for the Wounded Warrior Project, so you can't beat that."

Vice President for the event Lucas Barclay commented on the venue.

"Mr. Jaindl and the team from Jaindl Farms have proved to be wonderful partners," he said, "and the site has proved to be both picturesque and challenging for our participants."

In press releases, the location was referred to as "Philadelphia." The Press asked if it might be identified as the Lehigh Valley in the future.

"Possibly," said Barclay. "We love the support we received from the local community and townships and absolutely identify with the wonderful people of the Lehigh Valley."

Jaindl spoke by phone with The Press from the event. He said everything, including traffic for Tough Mudder, was going as scheduled.

Jaindl said although his involvement with Tough Mudder was initially limited, he became more involved since the event benefited the Wounded Warriors and he experienced the Mudder group's management style.

"I was sold on it," Jaindl said.