Through a place in south-central Montana we call the "gorge," where the trail is a ledge between a cliff rising vertically on one side and a frothing river below on the other, I recently watched a man descend on horseback leading a pack string followed by several riders. Though the trail through this stretch is good, many riders find it intimidating; the river's roar and the fine mist of spray keeps the rocky trail wet. It was clear, however, that passing through here was old hat to this man. He held a slim pair of leather split reins in his left hand in light contact with the horse's bit, and the lead rope of the front pack horse in his right.
As the group approached me, their leader suddenly stopped, and with a movement of his left hand so slight you could scarcely notice it, reined the horse broadside on the trail facing the drop-off to the river. For a moment I thought something was wrong, but the man wanted merely to take a photo of the group behind him. He laid the pack horse's lead rope over the pommel of his saddle, grabbed the camera that hung around his neck, aimed it with his right hand, snapped the photo, and dropped the camera back into place. Finally he picked up the lead rope again, and with a subtle touch of the rein to the right side of the horse's neck, deftly turned the animal left down the trail again.
What I'd watched was a traditional backcountry horse, a horse with a neck rein so complete and so subtle that a second hand was never needed on the reins, even on a treacherous trail. I respect all styles of riding disciplines and training, but for me the "complete" trail horse neck reins. The "using" horse of the mountain man, explorer, and cowboy traditionally neck reined, thus freeing one hand to carry a long rifle or to rope a steer.
The neck rein - that is, "push" pressure applied to a horse's neck opposite the side in which you're turning - is equally desirable for today's trail rider. It leaves one hand free to pony a pack horse, fend off from the tree your horse scrapes by too closely, operate a camera or pair of binoculars, or hang on in an emergency while still guiding the horse.
Neck reining also makes possible such advanced backcountry skills as dragging a dead snag of firewood back to camp or pulling a companion's horse out of a bog, when one free hand is needed to dally a rope around the saddle horn. Swapping reins from one hand to the other eases fatigue on a long ride and gives you a free hand on whichever side of your horse it's most needed.
A horse with a finished neck rein responds to the slightest touch of rein on neck and is guided by the smallest movement of your hand in the direction you wish to go. The relaxed harmony between you and the horse makes riding more enjoyable. One ride on such a horse is likely to spoil you, but the good news is that training a horse to neck rein is relatively easy. I begin teaching it on the very first ride, but most older horses from other disciplines can readily pick it up. Here's how.
(First, a distinction: I'm teaching the neck rein, not the sport of reining. Training a horse for reining competition is a specialized activity, and successful reining trainers have their own particular approaches.)
For starting most young horses, I prefer a snaffle bit, but the methods outlined here will work with a hackamore, as well. The mecate-type reins currently in vogue are fine if you're extremely adept at using them. I find, however, that eliminating any extra length and clutter makes my cues to the horse more straightforward, so I prefer a single looped rein of braided leather. And, for reasons we'll discuss later, I like one that's relatively short.
However, we'll strive to eventually switch to split (two piece) leather reins, because they're not only the most comfortable in a single hand, but the safest. I teach students in my clinics to avoid anything that can form a loop that might snag an arm or leg in a wreck, which can lead to dangerous complications. Two-piece, non-looping reins are less likely to snag.
Easy neck-rein training is based on three cues given simultaneously to your horse every time you turn him from the very beginning of training. First, whether with bit or bosal, your horse must already know how to yield laterally (to the side) with direct-rein pressure. Direct-rein pressure is that placed on the bit directly from your hand: With a rein in each hand, you apply left-rein pressure for a turn to the left and right-rein pressure for a turn to the right. If your horse lacks this training, go back to basics, consulting a reputable trainer or clinician if you need help.