Trail traffic
The rain stopped, and scores of day hikers, mountain bikers and horse riders converged on the Mulholland Scenic Overlook trail, one of the busiest paths in the Santa Monica Mountains.
Gray clouds raced past shrubby hillsides, and soil turned to dark porridge. The path through Sullivan Canyon resembled a fossil bed of hoof divots, knobby boot prints and gracefully curving bicycle tracks. People come for fun but often find conflict.
“You see those!” said Jim Frapton, a day hiker from Los Angeles, pointing to deep grooves from bike tires. “The mountain bikers are killing this forest! They come around corners at 30 mph! They’ll kill me someday, or I’ll kill them first.”
Such discord echoes across California as well as Moab, Utah, the Denver area and most anywhere cities lap against mountains. As competing users crowd onto trails, they blame one another for ruining their outdoor experience yet often overlook how their own activity affects trails and other users. Hard feelings sometimes result in fistfights, sabotage and lawsuits.
Experts say trails were not designed for so many different users, which exacerbates the problem.
“Almost since mountain bikes were invented, there have been conflicts over trail use,” said Pam Gluck, executive director of American Trails, a multiuse advocacy group. “Everyone blames someone else for trail damage, and each group has different expectations.” Hikers point fingers at mountain bikes, and cyclists blame horses, but all users contribute to erosion. Studies show that hiking boots and bike tires cause similar erosion, but horse hoofs do the most damage.
In one key study, two Montana State University scientists installed pipes to simulate rain across 108 portions of trails in and around Gallatin National Forest. They hiked and rode bicycles and horses 100 times and measured how boots, hoofs and tires displaced soil.
They found that hikers and horses “have more surface contact than
The study, published in 1994 in the journal Mountain Research and Development, also concluded that wet soil erodes more than dry ground, though the study examined only a few soil types.
In a separate but similar study, a pair of Canadian researchers at the University of Guelph in Ontario hiked and biked 500 times across four plots, each a meter long, in Boyne Valley Provincial Park, then counted the plant stems and plant species and measured the soil displacement in the affected ground. They found that both activities eliminated plants on the path and increased the amount of upturned soil by 54%. (The study only examined bikes and hikers moving downhill on dry trails in deciduous forest.) The findings, published in 2001 in the journal Environmental Management, show “that at a similar intensity of activity, the short-term impacts of mountain biking and hiking may not differ greatly.”
But hiking advocates say those studies don’t consider the extended range of bikes. “If a mountain bike travels 50 miles in a day, and hikers travel only five miles, the destruction caused by bikes is 10 times greater,” said Michael Vandeman, a San Francisco hiker who lobbies to close trails to cyclists.
Real forest damage, say hiking and biking enthusiasts as well as experts, is caused by poorly designed trails.
National Park Service officials say they can build lots of trails, but they all erode in time. “Once rainwater begins following a rut created by a trail, the soil will eventually become damaged,” said Steve Griswold, a trail builder at the Golden Gate National Recreation Area. “If a trail is designed properly, no one group will do more damage.”
Off-path destruction is another concern. It occurs when hikers and riders strike out to form new routes or find sites not connected by trail. Said Gluck of American Trails: “A good trail must anticipate what people want. If there aren’t any trails leading to a fantastic overlook, hikers will create their own. If signs don’t clearly communicate where trails lead, people will cross back and forth.”
Outdoors users often hit the trail with strikingly different expectations of what fun is all about. Social scientists say those hopes lie at the root of conflicts.
U.S. Forest Service studies show that whereas hikers frequently seek tranquillity, mountain bikers want adrenaline. Hikers polled in the Los Padres National Forest in 1989 said they objected to mountain bikers because they ride too fast, have difficulty stopping on blind corners and startle equestrians and hikers.
“Bikes are silent and fast,” said Jim Absher, a social scientist with the Forest Service. “If you’ve ever experienced someone roaring around a corner at 30 mph, it’s terrifying. That feeling is the opposite of what hikers want from a forest trail.”
Back at the Mulholland trail in the Santa Monica Mountains, Frapton dittoed that. “I come here to relax, but it’s impossible with all the bikes constantly zipping past,” he said. “These paths were built for hiking.”
But a mountain biker prepping his bike nearby disagreed. He said cyclists are not unmindful of hikers.
“I always make it a point to be courteous to hikers,” said Jerry Flattery, 48, of Los Angeles, sitting atop his silver mountain bike. “There’s more bikers out here than hikers. If we use it more, why shouldn’t it be ours?”
Despite safety concerns, accidents seem rare. A 1993 study of 40 Forest Service managers found that only one hiker had been injured by a mountain bike in the previous year.
Another federal survey of 1,400 users in California’s Los Padres National Forest in 1989 found that only 15 bike and hiker encounters were potentially harmful, and the only accident involved bikes colliding with each other -- when riders tried to avoid a hiker.
To prevent conflict, officials and trail users call for more paths to separate bikes, horses and hikers.
“If I want to encourage bikers to go one direction and hikers another, signs are ineffective,” said Joey Klein, a trail building specialist with the International Mountain Bike Assn. “Instead, I’ll have the trail go through sand. Bikers hate sand, but hikers love it.”
Klein designed a Black Canyon trail in Prescott National Forest in Arizona with water crossings that attract equestrians and dog walkers but deter bikers.
The goal, Klein said, is to create trails that encourage users to move at the same speed -- like the rocky paths around Fruita, Colo., that force bikers and hikers to slow down.
“Hikers want to get to the summit as fast as possible, but bikers don’t care about vistas,” Klein said. “Instead, they want hills that feel like a roller coaster.”