The following guidelines are from the IMBA Library

Trail closures are quickly becoming an every day occurrence. The equestrian and pedestrian lobbyists are more organized politically and financially than the mountain bike community. And let's face it, mountain bikers have not always been model citizens. Our own behavior has shut down many trails. We can stop this downward spiral of trail closures if we get our collective act together. One step is to start acting more responsibly. To that end here is a set of guide lines on how to act around man's original steed.

Always be alert for horses on multi-use trails.

Yield to them when possible. At a safe location, bring bicycle to a halt and remain in position. Many horses are spooked by the sight of and quick action of bicycles. Therefore, upon stopping, remain still and speak softly to have a calming effect on the horse.

If the rider stops the horse, converse with rider. Promote a positive relationship between user groups by encouraging a friendly, courteous meeting.

The rider may choose to move the horse on without stopping. This may not be due to a lack of courtesy, but rather due to a decision that the horse may be agitated and is best handled by urging him on past you. However, in some cases the rider may decide that he can best handle his horse by having you move on and request you do so. This is more apt to occur with a hiker or bicyclist than with an ATVer because of the noise created by the ATVer. Expect the rider to advise you.

What you should do when overtaking a horse/rider

A bicycle is generally quiet and is not heard by horse/rider. Signal by horn, bell or calling out that you are approaching. Stop. If horse is not agitated by your presence, proceed on. Otherwise, allow rider to move horse to rear before proceeding.

Many horses are well conditioned to traffic, and your presence would be undisturbing. Some are not, in which case following this protocol will create a smoother, safer passing.

Helpful Knowledge About Horses

A horse is a wandering, grazing animal that does not hunt other animals. However, in his natural habitat, he is hunted by other predatory animals. His defense against threats is speed. With only a 50-yard head start, no predator in the world can catch him. He is the fastest living animal at any distance over a quarter of a mile. Some cats (cheetahs) and some antelopes can attain higher speeds than the horse for short distances. For 100 yards or so they may even go twice as fast as the fastest horse. But they cannot maintain that speed.

To be sure that the horse has a margin of safety, nature has endowed him with a fantastic warning system. His sensory receptors alert him to approaching danger and prepare him for instant action to escape. Horses do not have much reasoning power. They do not have the ability to question or think about a situation. A horse's alarm system operates through use of his eyes, nose, sense of smell and instinct. This sensory system depends first on sight and hearing, and to a lessor extent, on the sense of smell.

Most experts believe horses cannot distinguish between colors and do not have a good depth perception. A horse has the ability to use both binocular and monocular vision. However, a horse has a much better field of vision that a human - a 340 degree range.

Without color or depth perception, the horse has some trouble differentiating detail. He sees lighter and darker shapes. A hiker with a backpack may look like a huge animal. In this flat, colorless panorama, motion sets off his alarm system. A horse's main weapon in getting to security is flight. However, if he is cornered with the option of flight removed, a horse will resort to kicking with his hind feet where he can ward off danger with bone-crushing kicks.

Keep in mind that a horse's difference in color, depth perception, and vision affect how he views his world. Generally, his reactions to his environment are based upon instinct due to his alarm system, which has ONE PURPOSE - to alert him to danger and move him to security.

A horse that reacts when meeting a biker by attempting to run simply sees you as a threat and is responding by instinct. A horse that "cuts up" when he sees you may be attempting to flee but is under restraint by the rider. A skilled rider will bring the horse under control. Understand that is natural for a horse to view you as dangerous when he does not see you well. Keep in mind that soft talk will help to reassure the horse that you are no threat.

Always keep in mind that a horse is easily spooked by strange sights and sounds. Do not attempt to pet horses. Although most horses are docile, this might be one of those occasions your action would spook him, and he might attempt to kick you.

Recognize that different skill levels exist among horse riders. Those less skilled may not be adept at handling a badly spooked horse.

Regardless of rules and etiquette, COMMON SENSE SHOULD PREVAIL. Always think safety.