Through two decades of bitter experience what we have learned here in

Marin County, the so-called birth place of mountain biking, is that

this sport is destructive to the environment and incompatible with

other park users. While it may not be immediately apparent, wildlife

is adversely impacted by vast numbers of cyclists who, by virtue of the

mechanical advantage their bikes afford, are able to penetrate deep

into sensitive wildlife habitats that, through their otherwise isolated

nature, provide safe haven for countless species that cannot coexist in

close proximity to people. The continued wear on trails by bicycle

traffic is particularly destructive owing to the fact that once

tolerated, the sport draws people not only from the immediate locale,

but from communities far distant. Here in Marin, on any given week

end, and even week day, cyclists routinely come to ride our trails from

as far away as San José and Sacramento, 63 and 86 miles miles away. As

a consequence, the flow of wheeled traffic on trails becomes massive

and the erosion it causes is often destructive beyond the parks’

ability to repair. Worse, once cyclists were granted access to a park’s

trails, they typically refused to abide by regulations meant to govern

them and minimize their impacts. Speed limits are considered a joke.

Illegal trail building has become rampant in the San Francisco Bay

Area, with literally hundreds of trees and their associated undergrowth

destroyed by cyclists dissatisfied with any limits placed upon them by

park management. Arrests, convictions and fines levied against mountain

bikers caught in the act have not stopped this pernicious activity.

Aside from these impacts, mountain biking has also caused numerous

accidents to horseback riders whose mounts, frightened by speeding

bikes appearing out of nowhere, have sometimes bolted and thrown their

riders. Because people on foot are usually able to get out of the way,

cyclists often do not make an effort to avoid them, but with shouts of

"commin’ through," simply run them off the trail. Those who fail to

make way often find themselves in ugly confrontations with gangs of

abusive cyclists, some of which have been violent. The long term

result is that other park users, finding their park experience

increasingly distasteful, eventually are displaced. China Camp State

Park is a classic example. While some of its trails are reserved for

equestrian and foot traffic, all have been taken over by mountain

cyclists. Speed limits are unobserved. Hikers and equestrians seldom

visit the park anymore; it has become a de facto mountain bike park.

I implore you to reconsider opening any portion of the park to the

sport of mountain biking.

Frank Lurz