John Mack has left the group over disagreements with founder Jacquelyn Hughes as to how many horses should be removed from the Salt River herd according to a report by Phoenix New Times.
That shifts management responsibilities to Hughes for five years if AZDA was to select her proposal, which is not her style.
As a wild horse removal contractor, she wants to get in, get the job done and move on to the next opportunity.
By contrast, the Salt River advocates have stayed the course, which is necessary to sterilize the mares.
Western Horse Watchers Association 