The Navajo Nation says about 191 feral horses were found dead Wednesday in a stock pond in Gray Mountain.
Tribe officials said foul play is not suspected and the horses died due to drought and famine.
“These horses weren’t shot or maliciously killed by an individual,” Navajo Nation Vice President Jonathan Nez said in a release. “These animals were searching for water to stay alive. In the process, they, unfortunately burrowed themselves into the mud and couldn’t escape because they were so weak.”
An official with the Navajo Nation's Office of the President said the horses were found "anywhere from thigh to neck deep in the mud," while some were "even buried beneath others."
A graphic photo from the scene shows a cluster of horses in and around the dried up pond.
Navajo Nation President Russell Begaye said the incident "exemplifies the problem the Navajo Nation faces in an overpopulation of feral horses."
According to a release, there are an estimated 50,000 to 70,000 feral horses on the Navajo Nation.
"The occurrence of horses dying at this particular watering pond is not a new but a seasonal issue," the release said.
The Associated Press reports that the Navajo Nation has struggled when it comes to managing larger populations of feral horses.
President Begaye said the process of managing the horses begins at the local level where individual communities can request roundups. But, the AP writes, "public outcry has halted such efforts in the past."
Navajo Nation officials said they will work to accelerate decomposition by spreading hydrated lime over the animals. The horses will then be buried onsite.
“This is our most humane and safest option,” an official said.
Officials said the plan does not pose any threat to groundwater, and the watering pond will be closed off and a new site will be opened elsewhere.
"Cameron Chapter officials are working on several chapter resolutions for an emergency drought declaration, to utilize emergency funding and to withdraw five acres at the site," a release said.