The horses graze as they please, resulting in ruined wheat crops, overgrazed rangeland, harm to other wild species and the occasional impregnated mare from a wild stallion, say tribal officials.
But limited budgets and limited options for finding new homes will prove a challenge, Gordy Schumacher, the tribal agricultural and forestry manager, told the East Oregonian.
The tribe's plan to control the population, approved last year, calls for a roundup of all the wild horses on reservation land. The goal, Schumacher said, is a population of 50 to 100 horses on the south side of the Umatilla River, and none north of the river, in agricultural areas.
Using helicopters in their first effort, the tribes drove fourteen horses into corrals last month. Five, however, did not sell at auction. They will be offered to tribal members for free next Wednesday.
The tribe's plan says horses are to be offered at auction first to tribal members and then to the general public. Those that don't sell are offered for free to tribal members and then the general public.
"Then I don't know what to do," Schumacher said. He said he has room to board only 30 horses. He said the tribes don't want to resort to slaughtering the horses, and they are exploring every option, which is why he placed a mare with a severely
injured rear leg and her foal with a local sanctuary.
"Because the mare was injured, it was either euthanize her or see if the sanctuary would take her," he said. "We're just getting going," Schumacher said. "It's going to be a learning curve and that means we're going to be making a lot of adjustments."
For now, he's just hoping the hay budget will get him through the next month. "It's going to be tight," he said. "We don't have much room for error here."