Robin and Gary Wadhams are dedicated volunteers who travel regularly to Colorado’s Sand Wash Basin Herd Management Area to administer fertility control via dart guns to wild mares, aiming to curb the growing wild horse population. Their work is part of a broader, longstanding effort to manage over 1,400 wild horses in Colorado, where populations exceed sustainable levels set by the Bureau of Land Management (BLM). Fertility treatments like PZP vaccines help reduce foal births, offering a humane alternative to costly and controversial roundups that remove excess horses for captivity, which strains federal budgets and often causes stress and injury to the animals.

Colorado has recently taken a more active role in wild horse management by passing laws to fund professional darters and establish a state wild horse program, supplementing volunteer efforts like those of the Wadhamses. Despite these advances, funding remains uncertain amid budget constraints, and roundups continue. The state’s approach aims to serve as a model for other Western states by focusing on fertility control to maintain sustainable herds, reduce the need for roundups, and protect the ecosystem, though challenges persist in locating and darting the elusive horses across vast, rugged terrain.