Dr Carbonell is described as a co-founder of the New Paradigm Trail Group, a group which has declared the country roads and trail management plan in the area a failure, saying there is not enough access for bikes.

Open Space Superintendent Ari Golan says the fine for riding illegally on open space land is $199 including court costs. The fine for a second offence is $410 and all violations after that cost up to $615.

Resisting arrest meanwhile carries the maximum punishment of a $1,000 and imprisonment in a county jail for up to a year.

The doctors were riding the Piedmont Trail in the Baltimore Canyon Open Space Preserve on December 12th when they were caught.

Sheriff’s Lt. Jeff Edwards said: “They were seen by one of the open space deputies riding on a trail they were restricted from riding bikes on. The deputy attempted to stop them and they rode away from him.”

The deputy was then however able to catch up with the mountain bikers, grabbing Cameron’s arm to stop him and later identifying Carbonell.

Carbonell is quoted as having said (in February of 2017): “I don’t want to be 65 years old before I see my vision for trail access sharing in Marin County implemented.”

Linda Novy of Fairfax, a Marin Conservation League board member, said, “These guys were breaking the law and then they tried to evade it. I think it is really shameful.

“This is really proof that enforcement is very necessary. There are some people, and these are examples of those people, who just don’t think the rules apply to them. We may never get them to comply unless they’re arrested.”

Cameron has pleaded not guilty to both charges, while Carbonell’s arraignment is scheduled for January 24.

Update: We have been informed that the riders in question were not pursued for citation for riding an illegal trail, and that the trail they were riding is actually legal for mountain bikers to ride during the day. The reason they were pursued was for riding the trail at dusk.