The damage to our local parks and trails by Mountain Bikes is a critical issue. Most of the trails used by mountain bikes in our local parks do not meet the criteria set Sierra Club policy: http://www.sierraclub.org/policy/conservation/mtnbike.aspx The only reason the Sierra Club considered supporting mountain biking was to gain the support of mountain bikers for protecting wilderness. It's time to admit that we made a big mistake, and correct it. Bicycles are considered vehicles in California Vehicle Code. Off-road bicycles are thus an "Off-Road Vehicle" and have no place on trails where other vehicles are prohibited.