We find the legend of Dead Horse Point at Utah Travel: “Dead Horse Point State Park is perhaps Utah's most spectacular state park. Dead Horse Point is a promontory of stone surrounded by steep cliffs near Moab, Utah. The overlook at Dead Horse Point is 6,000 feet above sea level. Two thousand feet below, the Colorado River winds its way from the continental divide in Colorado to the Gulf of California, a distance of 1,400 miles.
“Before the turn of the century, mustang herds ran wild on the mesas near Dead Horse Point. The unique promontory provided a natural corral into which the horses were driven by cowboys. The only escape was through a narrow, 30-yard neck of land controlled by fencing. Mustangs were then roped and broken, with the better ones being kept for personal use or sold to eastern markets. Unwanted culls of "broomtails" were left behind to find their way off the Point.
“According to one legend, a band of broomtails was left corralled on the Point. The gate was supposedly left open so the horses could return to the open range. For some unknown reason, the mustangs remained on the Point. There they died of thirst within sight of the Colorado River, 2,000 feet below.”
The banner image from the BLM is a view of the Shafer Trail and Colorado River below Dead Horse Point.