BILL SPARKES/Acorn Newspapers Once a month, when the moon is completely full, a group of Simi Valley trekkers answer the celestial body's beckoning call.

The hikers, mostly middleaged residents with regular day jobs, gather in the parking lot of Simi Valley High School at nightfall. That's where they meet up with group leader and Simi High Principal Steve Pietrolungo.

"Mr. P," as he's affectionately called, started the informal group six years ago after going alone on a hike under a full moon. He enjoyed the lighted path and nighttime climb so much he decided to invite others along the next time he went.

Colleagues, friends, his fellow Rotarians and sometimes even students now gather each month to walk the moonlit Simi hills.

"It's great being out at night when you don't need a flashlight," Pietrolungo said. "You see a whole different bunch of things you don't see during the day."

Kim Baker, a Simi Valley resident and assistant principal at Channel Islands High School, has been a moonlight hiker for three years.

Steve Pietrolungo "I've always wanted to hike the hills of Simi but I never would have gone out on my own. So when Mr. P told me about the night hikes, I gladly joined in," Baker said.

Pietrolungo, who started as principal of Simi High last year, said his love of outdoor exploration started as a youngster.

"I've been hiking since I was a kid," said Pietrolungo, who grew up in Canoga Park. "When we were kids, the neighborhood stopped in my backyard. All the Santa Susana Mountains were our playground."

Despite the ever-expanding urban sprawl, there are still many wild places to go, he said. The group has enjoyed climbs from Rocky Peak to the surrounding canyons. This month's hike, held Oct. 7, followed a trail off Yosemite Avenue, a six-mile round trip.

Pietrolungo's wife, Elizabeth, who also works for the school district, sometimes joins the hikers "to keep moving and enjoy the people who go on it and the full moon and have a good time."

The distance of the hikes varies from two to three miles. The longest trek the group ever went on was a 15-mile hike in Long Canyon.

Chris Mankey has been going on the hikes for two years. The Simi Valley High science teacher enjoys the camaraderie and identifying plants by moonlight.

"I like looking at the plants and trying to identify them and seeing the beauty of the valley at night," Mankey said. "The moon casting your shadow as you walk is pretty special."

The size of the group varies for any given hike. Some nights, 50 people may join in. Other evenings, when no one else shows up, the dedicated Pietrolungo heads out on his own.

Pietrolungo recalled one memorable hike around the Brandeis-Bardin Institute on Peppertree Lane. Not only was it good exercise, the group learned the history of the Jewish center from a fellow hiker who works there.

Pietrolungo finds established trails through the Rancho Simi Recreation and Park District or looks on the Internet. He hikes new trails during the day to get the lay of the land, then puts them on the night list.

Thus far the hikers have only spotted a few wild critters lurking about. According to Pietrolungo, a bobcat, a scorpion and a toad have, at one time or another, crossed the group's path.

"We usually go in large numbers and make a lot of noise," Pietrolungo said.

"Mostly huffing and puffing on the trail," he added jokingly.

If you'd like to get involved with the moonlight hikers, you can contact Pietrolungo via his school e-mail address at spietrolungo@simi.k12.ca.us.