I need a REALLY TUFF riding boot!?

I am trying to help a friend of mine find a new pair of boots. She is extremely hard on her riding boots. Shes out at the barn every day riding and doing rigorous chores. She rides intermittently throughout the day and does not have to option to have work boots to switch to for chores. So were trying to find a very tuff boot that she can have for a good length of time without destroying... Shes had multiple pairs of Ariat boots and they are just not cutting it for her. Do you know any brands or specific boots that she might want to consider. Thanks a lot!!