San Juan Trail: An Uphill Battle : The 11.2-mile path--which sometimes narrows to 15 inches--is a challenge for riders.

The San Juan Trail is a living timeline of Orange County history. Parts of the trail trace a path that for hundreds of years served the peaceable Juaneno Indians as a route from the coastal valley over the Santa Ana Mountains. Now, as many as 50 hard-core mountain bikers each weekend form a continuous and lively parade up and down the Forest Service trail.

Because of its length and variety of terrain, the 11.2-mile trail enjoys a reputation among advanced mountain bikers as one of the most difficult, challenging and fun trails in Southern California. It attracts mountain bikers from as far away as Central California in addition to local groups such as the Rads from Laguna Beach and B.G.R. (Billy Goat Racing) in San Juan Capistrano.

“San Juan is the descent trail,” said Carl Bauer, an avid mountain biker and manager of South County Cyclery in San Juan Capistrano. “Whiting Ranch and Crystal Cove are popular these days, but as far as a single-track, narrow trail that offers a challenge, there’s nothing like San Juan Trail.”

Beginning in Blue Jay Campground about two miles west of the El Cariso Ranger Station on the Ortega Highway, the trail descends 2,500 feet before it ends near San Juan Hot Springs. It is the longest of 11 trails in the Ortega Corridor of the Cleveland National Forest.

Bikers get a whirlwind tour of some of the most exquisite natural communities in Orange County’s high country.

Cross a fragrant, buckwheat-carpeted meadow, and fat alligator lizards and California quail scamper across the trail in front of you. Round a curve to dip abruptly into an oak-shaded arroyo, and acorn woodpeckers can be heard tapping. Swerve around the ridges, and manzanita whips your legs while afternoon mists drift about the landscape.

Halfway down the trail, south of 3,227-foot Sugarloaf peak, are remarkable views of the coastal region. On a recent afternoon, downtown Long Beach, the Palos Verdes Peninsula and Santa Catalina Island presented an awesome view.

Because most of the trail is on dry, shadeless ridgelines, overcast days offer the best touring conditions, enthusiasts say.

Because much of San Juan Trail was built for hikers rather than cyclists, the clearance between the chaparral sometimes narrows to 15 inches. Thus, right-of-way conflicts between meandering hikers and the much speedier bikers, which occur on all mountain bike trails, are exacerbated at San Juan. Hikers quickly learn to keep an ear out for approaching cyclists and step off the trail until they pass.

With heavy use, however, comes deterioration, and shrinking budgets have prevented the Forest Service from maintaining the trail for a couple of years, said Ernie Martinsen of the Trabuco Ranger District.

However, in recognition of the damage their vehicles do to the trail, groups of local bikers occasionally spend a weekend day repairing the switchbacks near the trail’s end.

The next official major trail clearance, funds permitting, is not scheduled until 1994, Martinsen said.

Most trail users go downhill only, meaning that about two-thirds of the trail requires no pedaling--but consequently, an extreme amount of braking. Heavy-duty components, such as front suspensions and disc brakes, provide a safer and less bone-jarring ride.

Among the trail’s hazards are dozens of hairpin turns, sometimes with nasty drop-offs just a couple of feet to one side.

In late May, a mountain biker plunged down one of these steep embankments and shattered a vertebra after his front wheel fell off. Loose pebbles or partly exposed rocks in the trail can also send a biker sprawling.

Bikers find little time to brood over the trail’s dangers, however; the changes in terrain occur suddenly, presenting fresh challenges that demand quick decision-making. Beginners are discouraged from riding the trail, and even many experienced cyclists take extra precautions.

“I recommend that people walk the trail first, to get familiar with it, and then ride,” Bauer said. “It’s not designed to be ridden faster than 10 m.p.h., but some people clear 30 m.p.h. They’re just asking to crash.

“Anyone who uses the trail should always take a friend, even if they’re just hiking it. You never know what can happen.”