I'm curious: since AFAIK one doesn't need a driver's license to ride a bike, what's the legal justification for the police demanding to see it?

You technically don't have to carry ID, but you are required by law to identify yourself. Some police misconstrue that as being required to show the license. You generally get the charges dropped in court, providing you were honest about your name, but it's a pain. I know because that's what my friend did - identified himself but refused to show papers. He was arrested on a Sat and had to spend the weekend in jail until the court opened on Monday.

Interesting. I've often wondered what would happen if you poached National Forest Wilderness trails. Mountain bikes are barred, but equestrians and pack companies are allowed to trash them as much as they want. It sounds like it's probably not worth it.

It's a fairly common misconception that bicycles are banned in Wilderness Areas due to their surface impact/damage to trails, but that is not the primary reason—all mechanized and motorized transportation is banned, because the spirit of the Wilderness Act is to preserve areas that restrict travel to low speed and more traditional forms of transportation—foot, horse, boat—and provide a place for people to travel more ponderously.

So while horses do certainly cause damage to trails in high use areas, that's not so much the motivation for allowing them but not bicycles.

I love mountain biking and think there absolutely should be places for it to be done, but I also love designated Wilderness Areas and their restrictions and protections.

Thanks -- I hadn't thought of it in terms of speed before. That said, I still think allowing horses in popular wilderness is a bigger mistake than allowing bikes. They turn a trail into either a trench full of shit-powder, a well-churned bog, or a set of awkwardly high and long steps meant for horses rather than humans.

It can definitely be an issue and a point of conflict in popular areas. It may be an issue that needs to be resolved with permits—limiting to a certain number of horse users per day per trailhead, for example. I hate permits, but if visitors are beginning to significantly impact the Wilderness (which the Wilderness Act is established to protect against) then permits to reduce impact are necessary.

Where I live, most Wilderness Areas are relatively little used and suffering from post-fire erosion, and so the trails often suffer from overgrowth and fading tread. As a result, horse use is actually quite welcome as it's currently below the threshold where it goes from helping keep the trail beaten in to actively damaging it.

You're lucky to live near relatively untrodden wilderness. In my experience as a hiker, many trails in the Sierra Nevada have been beaten into dusty trenches by horses, mostly thanks to pack companies. Quite a few in the southern Rockies have clay-rich soil, which horses will destroy when it is wet (so will bikes, but mud-riding is awful, so most riders will stay away). I have also been in some areas where horse traffic is the only reason that unmaintained Forest Service trails have not grown over.

I think banning commercial packers from the Wilderness would go a long way to fixing the problems with horses. Perhaps with some sort of licensing system, mountain bikers could be allowed as well.

The police can demand identification when issuing any citation: jaywalking, littering, etc.