Salt River Horses: A Call for Sustainable Management

The removal of three adults per foal born seemed extreme, so I decided to run some population projections in R-Studio. Using the SRWHMG’s end-of-2024 population (282), we calculated year by year how the population would be reduced if the three adults per one foal were implemented.

According to the SRWHMG Annual Report, there were 282 horses at the Salt River at the end of 2024. We added a modest amount (ten) to account for foals and possible reservation horses. Using this number, we will predict the population over the next ten years, accounting for average use PZP, supplemental feeding, migration of reservation horses, and drought conditions predicted for Arizona for the next ten years.

The Salt River horse population over the next 10 years, incorporating:

  • Starting population: 292 horses (end of 2024)
  • PZP efficacy: average (assume 75%)
  • Foaling rate: 1 foal per fertile mare per year
  • Mortality rate: 6% (slightly elevated to account for drought conditions despite supplemental feeding)
  • Removals: 3 adult horses removed for every foal born
  • Reproductive mares: 50% female × 70% of those of reproductive age = 35% of population
  • Migrants: Neighboring Reservation Horses can move back and forth in and out of the Salt River territory. They must be accounted for, and we utilized random movement. We made calculations with and without migrants. For the purposes of this dataset, we will make the reservation horses non-breeding, although they may not be treated with PZP, and therefore fertile.

For the nerds amongst you… here is the R Code

©drmeredithhudes-lowder, all rights reserved 2025


In 2019, the Salt River Horse Collaborative was formed and the members sought to mange the horses in the Tonto National Forest. Special interest groups and government agents were included.
The Salt River Horse Collaborative was established to develop a long-term management plan for the Salt River wild horses in Arizona’s Tonto National Forest. Facilitated by the U.S. Institute for Environmental Conflict Resolution and CONCUR, Inc., the Collaborative included a range of stakeholders:

Wild Horse Advocacy Groups: Such as the Salt River Wild Horse Management Group (SRWHMG) and the American Wild Horse Campaign (AWHC), both of which emphasised humane, non-lethal management strategies
Federal, State, and Local Agencies: Notably, the U.S. Forest Service and the Arizona Department of Agriculture.
Neighbouring Tribes: Tribal representatives from adjacent communities.
Conservation Organizations: Including the Center for Biological Diversity, which advocated for significant reductions in the horse population to protect native ecosystems.
Ranching and Hunting Interests: Groups concerned about land use and resource competition.

According to the report from the Salt River Horse Collaborative Meeting, the land can only support 28-44 horses. However, the majority of the parties involved agreed that 100 horses were sustainable. Please read the full report in the download below. However, none of this effort has been put into practice yet.

CONCUR, Inc., & Keith Mattson, LLC. (2019, December 18). Salt River Horse Collaborative Final Report. Prepared for the U.S. Institute for Environmental Conflict Resolution.

Revisiting this graphic below, we find that the horses, assuming no reservation horses ever set foot on the Salt River, would be at the recommended 100 horses by approximately 2028. The RFP states that if a horse leaves the management area, it will be removed upon its return to the Salt River. It also includes fence maintenance which neatly solves the issue of reservation horses




Dr. Meredith Hudes-Lowder
May 5, 2025

The wild horses of the Salt River

In light of the recent uproar regarding the future of the Salt River Horses in Arizona, including the false alarm of a “round-up in progress”, I thought I’d take some time to jot a few things down. Bear in mind I am playing the devil’s advocate in some of these comments and I firmly feel those horses deserve the right to live free at the River. I do not feel they represent a safety hazard to anyone nor have there been any negative incidents involving horse-human interactions. Cool heads need to prevail and present the facts clearly and calmly. 

The Salt River Horses of Arizona are in danger of losing their freedom. Advocates are scrambling to find rationales for preserving this beautiful population of wild horses. You may read that they are descendent of Spanish Colonial Horses and therefore they should be protected. Unfortunately, as soon as domestic horses were allowed to interbreed with the Salt River horses over the years, the lineage became diluted and their historical value diminished. There is no test currently, that allows us to differentiate a wild horse from a domestic horse. This is the principal reason the United States Department of Fish and Wildlife denied the recent petition to make the mustang an endangered species. We cannot tell them apart from domestic horses. The wild horses have no genetic mutations that are unique and therefore they cannot be isolated or differentiated from the domestic population. Even conformation isn’t reliable as the wild horses are the result mixing different breeds and similarities as well as differences exist among both domestic and wild horses.
Other attempts at proving uniqueness are that the Salt River horses are the only horses that eat river grass. The consumption of aquatic vegetation is actually quite common in the the wild horses of Camargue region of France and in the ponies of Assateague and Chincoteague. So the “mermaid horses” or more correctly the hippocampus of the Salt River is mere fancy. Another point cited to set this population apart is that there are a lot of grey horses in the Salt River herds. Anyone who has been to Sand Wash Basin or Spring Creek Basin will tell you that there are a lot of grey horses at those horse management sites. It is a dominant color and therefore, rather common in every wild horse population. The presence of the dun color, which is frequent in the more ‘primitive’ or ancient breeds (such as Spanish Colonial Horses, Nordic breeds, and/or the horse’s wild cousin, Przewalski’s Horse) is present in the Salt River Horses, but duns are far more far more abundant in wild horse populations that are more isolated. The Pryor horses represent a more bottle-necked population and they have a large number of dun horses, more proportionally than the Salt River.

Instead of struggling to find characteristics which are unique to the horses of the Salt River, perhaps we ought to focus on what they represent. They represent freedom, they represent our heritage and they played a significant role in how the west was truly won. They are a beautiful addition to the landscape of Arizona and the Salt River would be empty without them. They remind us of the beauty of nature and they bring visitors to the Tonto National Forest every year. I have seen these beautiful horses and they have captivated me. Do whatever you can to help these horses. 
Senator John McCain, Phoenix office, 2201 East Camelback Road, Suite 115, Phoenix, AZ 85016. Main: (602) 952-2410 and Senator Jeff Flake. (P: 202-224-4521
 Neil Boswell – Forest supervisor 602-225-5201
Carrie Templin, Public Affairs Officer, Tonto National Forest. 602-225-5290

2015- a new year begins…


Corona’s Band. Sand Wash Basin, Colorado ’14
Happy New Year 2015

The past year was a wonderful one for Equus ferus- Wild Horse Photography. We were given the prestigious honor of participating in the Cloud Foundation Art and Music Festival in Colorado Springs over the summer and, to our delight, we sold prints. We had a successful Mustang Walkabout (our summer trip out west to photograph the mustangs) and continue to sell photographs, calendars and prints. We opened an e-store at Red Bubble and are slowly adding to the items fans may purchase.  If you see a photo you’d like as an iPhone cover or mouse pad- or even correctly proportioned for an iPhone or Android (those are free), please don’t hesitate to ask; we can make it happen. Remember all net proceeds from our sales go back to the mustangs!!!

Perhaps the most important event in 2014 was attaining a quarter of a million fans and later passing the 300,000 fan mark. Without our fans, we are just another ordinary Facebook horse-related page. So by way of thanks, we will continue to randomly give away items such as our 2015 Calendar “The Stallion Edition”, and next year, we’ll have The Foal Edition” so stay tuned.
Picasso of the Sand Wash Basin, Colorado ’13
We are planning our summer 2015 Mustang Walkabout and we will visit the Sand Wash Basin, the McCullough Peaks, the Pryor Mountains, Little Book Cliffs and anything interesting along the way. However, before the summer, I will visit the Salt River in Arizona while attending a Mayo Clinic medical conference. I am probably the only person who finds medical conferences based solely on their proximity to wild mustangs. In the fall I will be in Salt Lake City for another conference and therefore will be obligated to visit the Onaqui HMA.
This summer also saw an end to my right anterior cruciate ligament, my medial collateral ligament and both meniscus were torn in my right knee. Since I performed this amazing orthopaedic trick two decades earlier, the ligament used to repair my torn ligament had to be borrowed from a cadaver. I will be spared during the Zombie Apocalypse since I already have a zombie part in my knee, or so my daughter Abigail cheerfully informed me. I had to take an unintended break from riding, Okinawan Kobudo, and even my 34 string Celtic Floor Harp- but I am back at the harp, will start up Kobudo in February and riding will wait until the spring. I was however, able to remain in school this semester, continued editing/posting photos during my convalescence and did not have to take much time off from my job.
I am hoping in 2015 to continue editing the photos collected throughout the year and to have an amazing time with the mustangs so we can bring them to you. I am always available to anyone who is interested in going out to see them; it is easier than you think- just email me. If you happen to be in the neighborhood of the horse management areas in the summer… I’ll guide you out there myself.

We will also be starting a series on ‘Equine Coat Colour’ where we’ll explore the genetics behind the marvellously coloured mustangs… 
Best wishes for health, happiness and joy for 2015
Cloud and I. Pryor Mountains, Montana ’14

Back once again

I will be starting, or I should say ‘restarting’ the Equus ferus Blog – I had one of those password moments and kept forgetting to change the password and write it down somewhere I’d remember… So we are up and running . We just returned from Spring Creek Basin, Salt River and Little Book Cliffs. It was a wonderful trip- we met up with our friends Karen McLain and TJ Holmes– you’ll see photos shortly. In the meantime, check back from time to time…

Meredith

Myself and my daughter Abby who is also an Equus ferus- Wild Horse 
photographer at Spring Creek Basin, Colorado 
February 2014