Making the 90-degree turn at the corner of the field requires real teamwork between a skilled driver and a well-disciplined team of horses. The three horses on the left side of the header turn 90 degrees to the left and walk outward, while the three horses on the right simultaneously back up. The horses on the right are hitched so that they can pull back on the header as they back up. The resulting motion causes the header to pivot in place. Photo by Wendell Love.