On the trail my horse always wants to be in the lead how can I control that?

A horse that insists on being in the front of the group on the trail is displaying a behavior rooted in a combination of herd dynamics, anxiety, and in many cases a training foundation that has allowed the horse to make his own decisions about pace and position rather than deferring to the rider. Some horses are genuinely more forward and dominant by temperament and find following other horses genuinely stressful — they are not being willful so much as anxious, and the anxiety drives them to push to the front where they feel more in control of their own safety. Others have simply learned over time that surging forward produces the desired result of being in front, and the habit has become self-reinforcing. Rate work is the primary training tool for this problem, and it should be done both on the trail and in the arena. A horse that responds reliably to your seat and leg to slow down, speed up, and maintain a consistent pace regardless of what other horses are doing is a horse whose position in the group becomes your decision rather than his. Practice rating your horse at the walk and trot behind another horse in a controlled environment before taking the work to the trail where the emotional stakes are higher. Every time the horse surges forward, bring him back softly with your seat and a light rein. Every time he holds the pace without surging, release completely and let him walk freely. Circles are your most practical tool on the trail itself when the horse surges ahead of his intended position. When he pushes forward past the point you want him, quietly bend him into a small circle, bring him back to the pace you want, and then straighten him out in the position you want. The circle slows the horse without a pulling battle, redirects his attention back to the rider, and makes pushing forward produce additional work rather than the reward of being in front. A horse that figures out that surging ahead results in circles while staying back results in straightforward easy walking will recalibrate his choices fairly quickly when the application is consistent. Mixing up the order within your group on a regular basis helps desensitize the horse to his position over time. Alternate between leading and following on every ride, and spend deliberate time in every position — front, middle, back — so that no single position carries more emotional weight than any other. A horse that has spent hours in every position without anything bad happening develops a more neutral attitude toward position generally, and the urgency to be in front diminishes as the association between front position and safety fades. That process takes months of consistent work rather than a few rides, but the horse that comes out the other end genuinely comfortable in any position is a dramatically more pleasant and safe trail partner.