A Unique Group of Volunteer Bikers Patrols Backcountry : Outdoors: The National Park Service relies on the 120-member Mountain Bike Unit in Ventura and L.A. counties to help keep trails clean and safe.

Just 30 seconds into his Sunday morning park patrol, veteran mountain biker Joe Dillman spotted his first call to duty: a soggy tissue hooked over a spike of grass.

Swinging off his mountain bike, Dillman plucked the raggedy scrap and tucked it into the pouch strapped around his neon-yellow jersey. “We don’t like trash on the trail,” he said.

Two hours later, Dillman came across a more serious challenge--a helmetless biker had tumbled while speeding down the steep slopes of Sycamore Canyon in Point Mugu State Park, and was complaining of dizziness and a sore back.

Fellow patrollers Jim Acosta and Terry Harman took over with first aid and sympathy for the wounded biker, managing to sneak in a few plugs for helmets as they dabbed his scraped-up knees with water.

Trained by the National Park Service and the Concerned Off-Road Bicyclists Assn., some 120 volunteers patrol state and federal parkland to help overworked rangers. In groups of three to five, they set out each weekend to pedal across backcountry trails, along the way encountering everything from half-filled beer bottles to half-conscious accident victims.

The Mountain Bike Unit, which covers both Ventura and Los Angeles counties, is the country’s only volunteer pedaling patrol group, according to founder Ross Blasman. At age 69, Dillman is the senior volunteer in the unit, which includes one 16-year-old and several husband-and-wife teams.

“I figured it was better to wear out than rot away,” Dillman said as he maneuvered his bike up a steep, rocky path. Working up a sweat seems more enjoyable than “sitting around watching liver spots grow,” he added.

Since the first Mountain Bike Unit was formed six years ago, the patrollers have helped hundreds of lost, injured and thirsty pedalers. They also give directions, distribute parks brochures and set up speed traps on steep hills to stop bikers from zooming recklessly by.

“It’s a way to give back to the parks instead of always taking,” said Thousand Oaks resident Walt Bird, 52, who patrols about once a month.

In their bright nylon jerseys splotched with official park service badges, the bikers attract considerable attention as they follow well-traveled routes through the mountains, cheerfully flagging down passers-by to offer information and advice.

Sammi O’Neal, the toppled biker suffering from a bruised head and a severe case of “road rash” scrapes, was relieved to see the patrol Sunday morning in Sycamore Canyon. He gladly submitted to the application of stinging antiseptics, repeated pulse counts and insistent questioning: “Are you dizzy? Do you feel nauseous?”

Feeling better after 20 minutes of first aid, O’Neal sat in the shade awaiting the arrival of a park ranger who would drive him back to the parking lot. After admitting that he had been whizzing down the hill at 35 m.p.h.--more than double the posted speed limit--O’Neal had only one concern.

“Do you guys write citations?” he asked.

In fact, the mountain bikers do not have law-enforcement authority. For serious accidents or infractions, they call park rangers on their two-way radios. Just the squawk of the radio is often enough to persuade stubborn scofflaws to change their ways.

Because the National Park Service can afford only 10 full-time rangers for the entire Santa Monica Mountains, officials rely heavily on the volunteers, especially during hectic summer weekends. The park service also sponsors horse and foot patrols, but the bikers are the most visible.

“They’re a very well-organized and beneficial group,” said the park service’s regional superintendent, David Gackenbach.

Louis Higuera, a visitor from Florida, found that out first-hand when Dillman stopped him to suggest an alternative route, up some steep hills and through a picturesque trail. “It’s great to have someone here who knows the area,” Higuera said.

But sometimes, despite their pouches full of parks brochures, the patrollers don’t have all the answers.

When Thousand Oaks resident Brandon Scher flagged down the volunteers, he posed a tough question: “Why don’t they open this place up to motorcycles?” he asked, as his grandson, Zachary, tugged him along. Gesturing toward the dirt-speckled mountain bikes, he added: “It looks like too much work to get on one of those.”

Aside from their love of the outdoors, many volunteers join the pedal patrol because they want to change the image of bikers as speeding road hogs who mow down hikers and crash through delicate plants.

“Mountain bikers get a bad name because of a few that behave badly, so it’s nice to try to change that image,” said Holly Harman of Chatsworth, who trekked over to Rancho Sierra Vista off in Newbury Park for a Sunday morning patrol with her husband, Terry.

“These are not gonzo-type rides,” Dillman said. “They’re nice and relaxed. After all, the slower you go, the more you can observe and the more people you can talk with.”