Riding cross-country is never allowed. The backcountry is open to bike campers. Motorcycles and motorized bikes are not allowed. On narrow trails, stop and let hikers pass. In most instances you should stop, get off your bike, and go to the lower side of the trail.
Horses are often leary of unfamiliar things that are taller than they are.
Horseback riders will usually let you know what you can safely do around their horses. Keep your bike under control at all times Riding your bike at dangerous speeds can hurt you and other innocent people, AND it's against the law. Slow down or walk around blind turns. Roads and trails are often rough and may be rutted in places. Avoid creating ruts in soft or wet trails.