A week after a mountain biking mishap injured two equestrians and a horse in Novato, the incident continues to reverberate through social media, equestrian circles and the cycling community.

Many online commenters have condemned the young mountain bikers who allegedly fled the scene, but others touched on issues of wealth and class, politics, land management and Marin County's alleged sense of entitlement.

"Marin is the problem. All the self-righteous spoiled brats can't get along," said a Facebook commenter who listed a Montara residency. "Seriously, if the biggest problem you have to deal with is your horse spooking when a kid on a bike approaches, you need to stop complaining. Accidents happen. Kids are irresponsible."

"Want to identify the mountain bikers?" a San Francisco woman posted on Facebook. "Ban the use of mountain bikes on public land until the bikers are identified. Their friends will squal (sic) like pigs."

"Equestrians act as though public trails are their private riding sanctuary," wrote a Facebook user who reported a San Anselmo residence. "Take responsibility for yourselves and your animals. And, like responsible dog owners, please pick up your animal's feces."

The incident occurred June 20 on a single-track trail in the Indian Tree Preserve in northwestern Novato. Two equestrians reported that a pair of boys on mountain bikes whizzed around a blind curve and spooked their horses, which threw the riders to the ground.

The equestrians said the boys, who appeared to be 10 to 12 years old, rode away despite their pleas for help. One of the riders, Lisa Zeppegno of Oakland, suffered spinal fractures and had to be airlifted to an ambulance.

The horse she was riding, Coco, ran away in panic and spent about 24 hours in a gully before a park ranger found her the next day. The horse, which belongs to Willow Tree Stables in Novato, suffered gashes to her nose and chest.

Marin County Parks, the department that oversees parks and open space, is still trying to identify the mountain bikers who were illegally riding on the single-track trail. Linda Dahl, the county parks director, said the parents should be held accountable.

"Information has been passed to us by people in the area," Dahl said Wednesday. "Sheriff's investigators are doing research and will be making contacts soon to determine if those identified were involved."

Curt Kruger, who owns Willow Tree Stables with his wife, Monte, said it could be more than a month of rehabilitation before Coco can go riding again.

"She's recovering," Kruger said.

Dahl said the department was "flooded" with comments after the incident. She compared the public response to that in 2009, when conflicts among bicyclists, hikers and equestrians prompted the county to develop the "Road and Trail Management Plan/Environmental Impact Report."

The plan, the product of three years of public workshops, will be presented at 10 a.m. July 23 at a joint meeting of the Board of Supervisors and the Marin County Parks and Open Space Commission.

Dahl said the plan will propose several policy changes and a "decision-making matrix" for modifications to roads and trails. But she said other changes have already occurred, such as increasing the fines for trail violations, switching some rangers' assignments from maintenance to enforcement, and recruiting additional rangers through Measure A funds.

Fines and penalties for illegal biking in open space range from $199 for the first offense to $615 for the third and subsequent offenses.

On Wednesday, the Marin County Bicycle Coalition sent the Board of Supervisors an email saying it is "deeply disturbed" by the incident.

"We are working on better signage in our parks and a Code of Conduct that could be distributed at bike shops and other bicycle gathering places," wrote Tom Boss, who is the "off-road and events director" for the coalition. "Please know that MCBC and the bicycle community takes this incident very seriously and we are encouraging those responsible to come forward."

Contact Gary Klien via email at gklien@marinij.com or https://twitter.com/GaryKlien