Steve Mentzer recalls the first time he took the Rachel Carson Trail Challenge, a 34-mile endurance hike, in 1999.

"I brought gear I would normally bring as a backpacker," Mr. Mentzer said. He carried a full backpack that day and wore heavy-duty hiking boots.

"I was able to finish, but I made it more difficult than it needed to be," he said. "I found that lightweight hiking shoes or running shoes were more than adequate, and you have to have as little weight on you as possible."

Mr. Mentzer learned from his mistakes that day, and, in 2003, he became events coordinator of the challenge, a one-day endurance hike covering almost the entire length of the Rachel Carson Trail, from Harrison Hills County Park in Harrison to North Park.

	Ed Yozwick, Post-Gazette Tracing the Rachel Carson trail from North Park to Harrison Hills County Park. Click photo for larger image.

This is the 10th year of the challenge, named after the environmentalist who wrote "Silent Spring," a groundbreaking book on the dangers of pesticides.

The challenge will be held from sunrise to sunset June 24, the Saturday closest to the summer solstice. This year, the hike starts in Harrison Hills and ends in North Park, unlike previous years when it started in North Park.

The hike takes people through streams, over hilltops and across different types of terrain. Hikers say the hills are the most challenging because the trail goes straight up and down them. No side routes are allowed, but checkpoints are every seven or eight miles, where hikers can get snacks and drinks.

The first year, 75 people took part. Last year, the hike drew 504. About 550 are expected this year.

"A big factor in drawing so many people is that it's not a race," said Mr. Mentzer, 41, of McCandless. "You don't have the pressure to beat the next guy, and it can be for people who have no ability to run a race."

Jim Ritchie, who came up with the idea of the challenge with Leo Stember, said one reason the hike draws so many people is because of the simple fact that it's a challenge.

"We're asking people, 'Are you disciplined enough, conditioned enough and do you have the will to take a challenge?' People usually respond to that concept," Mr. Ritchie said. "It's a healthy, wholesome, outdoor activity that can push people to their upper limits."

"It's a physical and mental challenge," said Diane Kostka, who will participate in the challenge for the eighth time this year. "Mentally, you have to be tough enough to stick it out, whether it's in the heat or in the rain."

"It's a great way to get out there and exercise," said Mr. Mentzer, who is in the software business. "It's better than just walking up and down streets. [Walking on streets] is good, but you don't get the perspective on the world that you get from the hilltops and along the river."

Mr. Ritchie and Mr. Stember came up with the idea of the challenge on the trail one day.

"We were on the trail, talking and wondering if anyone could do it in one day," said Mr. Ritchie, an administrative researcher from Oakmont. "So we decided to see if anyone could take the challenge and hike 34 miles in one day."

Mr. Ritchie's last year fully coordinating the event was 2001 because of his job. In 2002, he started to turn responsibilities over to Mr. Mentzer but still helps out.

	Steve Mellon, Post-Gazette Brian Jeffrey negotiates the steep terrain of the Rachel Carson Trail in Indiana Township in 2002. Mr. Jeffrey, of the Dorseyville section of the township, was taking part in that year's Rachel Carson Challenge endurance hike. Click photo for larger image.

Mrs. Kostka's husband, Joe, has been involved with the challenge for about seven years, volunteering and hiking the trail. Although the trail can be rough at times, Mr. Kostka said, it offers some advantages.

"You're hiking with a group of people interested in the same things you're interested in," said Mr. Kostka, 52, a tool and dye maker. "Also, it's a way to preserve the trails."

Proceeds from the registration fees, $35 for advance registration, $65 on the day of hike, help to maintain the trail, as well as the Baker and Harmony trails, all three of which are maintained by the Rachel Carson Trails Conservancy.

Hikers can register on the day of the event, but are encouraged to register early as it is limited to 600 people.

To register in advance, visit www.rachelcarsontrails.org/rct/challenge/rctc06.