A long time ago I rode in feedlots in Colorado and New Mexico. I was not an employee, but I was riding with friends who were “pen checkers.” Their job was to ride through pens of feeder cattle, and look for signs of illness, taking out any animals needing care.
As we rode I began to notice how the cowboys, and they were all skilled horseman as well, maneuvered their horses into the various positions required to perform the tasks they were paid to do. It was truly an education. The reins dangling from the saddle horn, the cowboy would have a little book in one and his other hand on the gate latch. With seat and leg signals, the horse would side pass to the gate, adjust forward to allow the latch to be released, back two or three steps to clear the gatepost, turn on the forehand around the gate so the cowboy never had to turn loose of the gate, side pass the gate closed and wait while it was latched. All the while the horse and rider team were to be wary to guard the gate against an attempted escape by a steer.
Over time I learned their method. Their horses were taught to move in response to weighting a seat bone, an invisible signal. The movement is modified by touches and positions of the riders legs. A leg pushed forward with pressure on the stirrup means stop and/or back up. Pressure at the cinch means move only the shoulder over. A touch at the back cinch of the saddle means move the hindquarters over. The opposite and leg is held off the horse, “opening the door,” so to speak. Then if the leg pushes between the shoulder and the other two spots, the horse “side passes” to open or close the gate.