There were three historic herds that inhabited the Sheldon National Wildlife Refuge.
The map below indicates the three locations where horses were once found in the Sheldon National Wildlife Refuge. Entering the Refuge from Denio in NV, traveling Rt 140, you continue past the Fish and Wildlife sub headquarters until you see the sign that says to Cedarvile. The sign is on the Right, the Road is on the left. That road is the gateway to the three historic herds of Sheldon.
The Catnip, Fish Creek and Badger herds all have unique aspects and have been established for more than a century, longer than the Refuge has been in existence.
Traits general of the horses in the herds of Sheldon are 15+ hand size, bays, sorrels, and white facial and leg markings. The groups appear to rarely mix so each group also has specific characteristics.
The horses called the Catnip/Round Mountain herd are very colorful, sorrels with flaxen manes and tails, overo paint, palominos, few buckskins. Fish Creek herd horses are larger bays and dark brown horses, some tobiano paints. Those of the Badger herd look to be a thoroughbred/quarter horse, sorrels, chestnuts, and bays.