February 6, 2003

Ms. Christine Ottaway, Project Co-Manager

The Presidio Trust

34 Graham Street

P.O. Box 29052

San Francisco, CA 94129-0052

Subject: Mountain Biking on the Presidio

Dear Ms. Ottaway,

I have recently learned of lobbying efforts by members of the mountain biking community for the inclusion of their sport into the Presidio Trails and Bikeways Master Plan. I am also aware of a conversation, conducted during the course of a bicycle ride, between mountain biking spokesman, Mr. Aaron Thies, and your colleague, Ms. Andrea Lucas, in which Mr. Thies sought to dispel concerns that mountain biking might be inimical to the overall welfare of the Presidio and its visitors. Subsequent to the conversation he published its details on a mountain biking news group, explaining to its readers that he had assured Ms. Lucas that her concerns were unjustified. If I may, I would like to contribute my own view on this subject, acquired over nearly two decades of experience.

Trail User Conflict:

From the earliest days of mountain biking there has been serious conflict between mountain bikers and other trail users. Such conflicts are not simply local, but common throughout the country and are well documented. Trail cyclists' refusal to observe speed limits, travel only on designated trails, and to yield right of way to people on foot and horseback have been the cause of innumerable ugly trailside altercations. On occasion, these altercations have escalated to violence. While trail cyclists admit to such nasty episodes, they stridently insist that they are rare, and that they are caused by only a "few bad apples."

Such is simply not the case. Countless letters of complaint from pedestrians and equestrians citing episodes of harassment, intimidation, near-miss collisions, speeding and reckless riding by mountain bikers were admitted as evidence in the 1996 9th Circuit US Court of Appeals case of Bicycle Trails Council of Marin v Babbitt and the US National Park Service. The volume of correspondence belied trail bicyclists' claims that such incidents are infrequent. In another instance 274 letters of complaint were instrumental in swaying the Midpeninsula Regional Open Space District to close seven preserves to mountain biking on December 1, 2000.

Cyclists' insistence that these conflicts are caused by only a small percentage of cyclists was decisively dispelled by the study conducted by Dr. William W. Hendricks on Mount Tamalpais in 2000, who found that speeding and refusal to yield to pedestrians was common to more than half of all mountain bikers observed. (See: Hendricks, W. W., Ramthun, R. H., & Chavez, D. J. (2000). Mountain bicyclists' behavior in social trail etiquette situations. Proceedings of the 1999 Northeastern Recreation Research Symposium. USDA Forest Service General Technical Report.)

Park/Trail User Displacement:

In Marin County's China Camp State Park, where mountain biking has been allowed on most of the park's trails, hikers and equestrians have for the most part disappeared. At Annadel State Park generous concessions have been made to mountain bikers demanding access to "single track trails," cyclists' euphemism for foot paths and bridle trails. Previously wide fire roads were re-constructed to 48 inch widths, desired by cyclists, by park management under the direction of a member of park staff who is an avid mountain biker. Following the completion of the project, mountain cyclists speeding down these narrower trails have made the outdoor experience for hikers and equestrians so distasteful that all but the most die-hard among them have abandoned the park altogether. In Mt. Tamalpais State Park, the Marin Municipal Water District, and the GGNRA the situation is the same: trails opened to trail bikes have been abandoned by people on foot and on horseback. For verification of the situation in Marin you may contact the Bay Area Trails Preservation Council at: <http://www.trailspreservation.org/>, or the Tamalpais Conservation Club: <http://www.tamalpais.org/>.

Trail Erosion:

Off-road cyclists repeatedly deny that mountain biking erodes trails. Often, they cite "studies" supporting their claim. These "studies," however, are the creative result of work done by mountain bikers themselves and do not take into account factors that cause erosion. Evidence to the contrary is universally abundant. I invite you to view the photographs of environmental damage caused by off-road cycling at: <http://www.wheeled-locusts.org/>. You may view more such examples found here, in Marin County, at: http://homepage.mac.com/terrialvillar/mountainbikedamage/PhotoAlbum22.html.

In the conversation between Mr. Thies and Ms. Lucas the subject of artificial trail surfaces reportedly was discussed. It is a fact that the subject of "trail armoring" has been of vital concern among many mountain bikers as of late, as has been the matter of "trail care crews," cyclists' euphemism for trail (repair) crews. They are of such significant interest for only one reason; mountain bikes frequently erode most trails so severely that without constant repairs they become impassable, even to people on foot. Make no mistake: mountain bikes damage the terrain.


Many trail cyclists share a contemptuous attitude toward trail restrictions. Often, this results in the destruction of fences, gates, turnstiles, and other barriers meant to keep bikes out of areas where their use is considered inappropriate, dangerous, or destructive. To avoid prosecution for riding on trails closed to bikes, cyclists have repeatedly torn down signs designating closed trails in order to plead ignorance when caught by rangers. In addition, trail cyclists have repeatedly vandalized the natural environment; ripping up vegetation, felling trees, and digging open the soil in order to construct trails more suited to their enjoyment. This destructive behavior has been nearly impossible to prevent owing to parks' usual lack of law enforcement personnel and monetary resources. Over the last 10 years of such vandalism in Marin County, despite the construction of many miles of illegal trails, there has been only one instance of a successful arrest and conviction. The arrest was accomplished only after three middle-aged men were discovered to have secretly cut a trail traversing 4 miles of GGNRA, Marin Municipal Water District, and State Park lands. Without adequate enforcement, vandalism of this sort simply cannot be stopped.

Impracticality of the Multi-Use Trail:

Mr. Thies reported that the width of the Presidio's "single track" trails, as measured by Ms. Lucas, is "generally about 3-4 feet wide . . .". Added to this, he explained that he "tried to convey why [single track] is treasured by mountain bikers. . . " and explained further that he told her that mountain bikers "crave technical rides with curves and terrain features . . .".

Trail Width:

With regard to trail width, it must be understood that the handlebars on a mountain bike are typically 24 inches wide, and that the width of a person's shoulders ranges in size, but can be as much as 22 inches or more. This leaves very little room for clearance on a 36 to 48 inch path. In addition, it should be noted that both cyclists and pedestrians tend to travel down the center of a trail or path, and that when moving in pairs, prefer to travel side by side. While it is certainly possible for pedestrians to "move over" to the sides of the trail when being passed, a constant repetition of this practice eventually becomes annoying, disruptive, and unpleasant. Added to this, the experience of repeatedly being passed by cyclists traveling at speeds of 15 miles per hour and more commonly makes pedestrians exceptionally nervous and apprehensive. These are not experiences sought by people come to visit parks.

Trail Use:

When Mr. Thies told Ms. Lucas that mountain bikers "crave technical rides with curves and terrain features . . ." he said a mouthful. This admission is entirely consistent with my experience of trail cyclists, and it is in complete accord with the advertisements, photographs, and stories published in mountain biking magazines. In the Oct 2 issue of "Mountain Biking Magazine," pp12 - 13, there is an advertisement that eloquently reflects the mindset of trail cyclists. In bold letters across a two-page spread the ad reads, "CONQUER DOMINATE OBLITERATE". The agency that put together that ad knows what mountain bikers want they're marketing professionals who know their customer base; they know exactly what mountain bikers "crave" speed, excitement, THRILLS, CHILLS & SPILLS. It comes as no surprise that, along with the mountain bikes, retailers are now selling sturdier helmets and body armor.

To put cyclists "craving" such challenges on trails used by pedestrians looking for nothing more than the enjoyment of a quiet walk in the natural beauty of place like the Presidio is to invite more of the same kind of conflict already extant in parks and open space districts that have allowed mountain bikes on their trails. The same ugly confrontations will ensue, and eventually strollers, hikers and joggers will be driven out. The park's trails will be abused until cyclists tire of them or they become unrideable, and bored riders will begin riding "off trail," cutting new routes across the Presidio's lovely terrain. Once the Presidio realizes the damage these bikes do and the trouble they cause for non-cyclists it will try, as others have tried, to "control" the situation. And, as others have learned, Presidio Staff will learn that the situation is uncontrollable. As they do everywhere else, mountain bikers will ride anywhere they like and do exactly as they please. The situation will get completely out of hand, and too late, Presidio Staff will discover that the genie has escaped forever from the bottle.

I was stationed on the Presidio as a soldier in the '60s and came to know what a magnificent treasure it is. I cannot begin to tell you how much its wondrous beauty and sublime tranquillity helped me to recover from terrible experiences I had when overseas. My heart truly breaks at the thought of its being abused and becoming such a hostile environment for pedestrians that they can no longer enjoy its quietude and peace. On bended knee I implore you, Ms. Ottaway, please protect this unique, lovely, irreplaceable sanctuary. There are so many other places, right here in the Bay Area, where mountain bikes are already allowed. Opening the Presidio's trails to them isn't at all necessary. Surely, this small island of peace and beauteous splendor can be spared.

Most sincerely,

Frank Lurz