young wild horse grullo colored stallion on the run in the pryor mountains wild horse range on the montana wyoming border in the

america animal big black caballus canter canyon chase chasing equus feral ferus free gallop galloping gray grulla grullo horn horse horses icon lighting male mammal mane montana mountains mustang one proud pryor pryors range rim roan rocky run running silver stallion states sunlit tail tree trot united usa walking western white wild wilderness wildlife wyoming young