Free living-only place: a model

Natural selection is Nature’s rigorous filter for genetic vigor. It is not cruelty; it is the mechanism that has shaped every free-roaming equid population for millennia. Mother Nature applies a suite of pressures: disease, extreme weather (drought, heat, cold), difficult terrain (rocks, potholes, abandoned fencing), competition among mares and stallions, predators (mountain lions, bears, wolves, coyotes), other wildlife risks, and the intelligence required to navigate them.

Individuals that cannot meet these challenges leave fewer offspring. Over generations, weaker genetics are suppressed and stronger traits advance. This process maintains the adaptive fitness that defines a truly wild herd.

Our Cultural Heritage herd is not a random collection of domestic horses gone astray. Some individuals still express the ancestral Dun allele (and related non-dun1 alleles) at the TBX3 locus: the wild-type camouflage pattern with dorsal stripe, leg bars and body markings that predates domestication.

Local fossils in the Cascade-Siskiyou Mountains document the deep presence of horses in this landscape.

Peer-reviewed scholarship, including the PhD dissertation of Dr. Yvette Running Horse Collin (University of Alaska Fairbanks, 2017), together with Indigenous Traditional Knowledge and other historical and scientific sources, challenges the Eurocentric claim that all American horses are solely post-Columbian Spanish introductions. Collin’s work synthesizes Indigenous accounts, historical records and scientific evidence to conclude that Indigenous horses of the Americas persisted through the Pleistocene, and that the original peoples of these lands maintained relationships with them long before European contact.

Our herd carries the genetic and cultural signature of that deeper history.

The herd once lived as unowned “feral” animals under Siskiyou County jurisdiction, roughly 20 miles northeast of Hornbrook, California. High-grading (selective removal of desirable individuals for sale or meat) was eroding genetic quality. Wild Horse Fire Brigade sought and obtained formal ownership recognition from the County, specifically to end illegal pilfering under the California Food and Agricultural Code and to stabilize the population.

Ownership transferred the herd into the legal category of privately held livestock, managed by William Simpson, Michelle Gough and the 501(c)(3) nonprofit Wild Horse Fire Brigade. That legal shift created both opportunity and responsibility.

Livestock-style management designed for domestic horses would domesticate the herd and destroy the very wild character and genetic processes we are trying to preserve.

Full hands-off “let Nature take its course” management on open range, however, risks unmitigated suffering during extreme drought years, when forage quality drops. With the same parasite load that is already present, the lowered nutritional value of the abundant forage creates a net loss of available calories for the grazing horses. (The primary seasonal rise in intestinal parasite pressure occurs in spring, when sugar content in the forage is at its peak, not during the late-summer and early-fall drought period.) This is especially challenging for older animals and lactating mares.

Wild Horse Fire Brigade therefore adopted a hybrid model, grounded in the BLM’s own Wild Horse and Burro Management Handbook (which calls for self-sustaining populations of healthy animals while protecting free-roaming behavior and genetic diversity), and updated with principles from the National Academy of Sciences and IUCN Equid Specialist Group guidance. Key elements of the plan:

• Allow natural selection to operate across the open range where the herd resides. Competition, terrain, predators, weather and disease continue to test individuals.
• Monitor body condition and intervene only at the margins during exceptional stress (such as the 2026 drought).
• Make supplemental high-quality alfalfa (approximately 50 tons this year, versus the normal ~30 tons) and water (1,000 gallons per day at the ranch) available at Wild Horse Ranch, the historic core of the home range, so animals that choose to visit can offset the sharpest nutritional shortfall. Full feeding of the entire herd would require roughly 1,000 tons of hay annually (hundreds of thousands of dollars) and is neither practical nor desirable.
• Provide targeted support (worming, and concentrated feed when feasible) to pregnant or nursing older mares that visit the ranch, reducing mortality risk without removing the broader selective pressures.
• Avoid routine intensive handling, confinement or selective breeding that would convert the population into a domestic herd.

This approach does not eliminate natural selection. The horses still face the full range of natural challenges on the open range: competition, predators, weather, terrain and disease. What it does is reduce the harshest effects of extreme drought, by offering a limited amount of extra feed and water at the ranch for the horses that choose to come in.

Even in a dry year, the open range itself still provides the great majority of the forage the herd needs (hundreds of thousands of tons available to all the herbivores in the area). The supplemental feeding is only a temporary cushion during the worst part of a drought, not a replacement for natural living.

It aligns with the BLM handbook’s emphasis on genetic monitoring and minimum viable population considerations, the National Academy of Sciences’ recognition that genetic diversity and adaptive capacity depend on natural processes plus careful management of small populations, and IUCN principles for maintaining wild equid fitness while addressing welfare in managed landscapes.

No system is perfect. Some animals will still fail Nature’s tests. That is the unavoidable cost of keeping a herd wild rather than turning it into a domestic collection.

Given the constraints of private ownership, open-range realities, finite resources, and the dual goals of genetic integrity and humane care, Wild Horse Fire Brigade’s hybrid plan represents the highest practical standard currently achievable: science-informed, transparent, and focused on long-term vigor rather than short-term aesthetics or zero-intervention purity.

The sources William E. Simpson II refers to:

• Collin, Yvette Running Horse (2017). The Relationship Between the Indigenous Peoples of the Americas and the Horse: Deconstructing a Eurocentric Myth. PhD dissertation, University of Alaska Fairbanks. archive.org ↗
• Imsland, F., McGowan, K., Rubin, C.-J., et al. (2016). Regulatory mutations in TBX3 disrupt asymmetric hair pigmentation that underlies Dun camouflage color in horses. Nature Genetics 48, 152–158. nature.com ↗
• Bureau of Land Management (2010). Wild Horses and Burros Management Handbook (H-4700-1). U.S. Department of the Interior. blm.gov ↗
• National Research Council (2013). Using Science to Improve the BLM Wild Horse and Burro Program: A Way Forward. National Academies Press. nap.edu ↗
• IUCN SSC Equid Specialist Group (ongoing). Conservation guidance and action plans for wild equids. iucn.org ↗ See also: Moehlman, P. D., ed. (2002). Equids: Zebras, Asses and Horses. Status Survey and Conservation Action Plan. IUCN.
• Cothran, E. G., and related BLM genetic monitoring summaries referenced in the Handbook and the National Research Council report (heterozygosity targets, and minimum effective population sizes of about 50 breeding animals, or about 150–200 in total, for acceptable diversity).
• Supporting population and selection literature, including long-term studies of free-ranging horses (for example the demographic and genetic work on Sable Island) on the effects of weather, density and resources on survival and reproduction, and reviews of gastrointestinal parasite dynamics in free-ranging equids under nutritional stress.