I used retrospective analyses to investigate relationships among terrain type, reactions of prey, and age and sex of prey and outcomes of encounters between mountain sheep (Ovis canadensis) and coyotes (Canis latrans). Adult females fled from coyotes more often when in open terrain and young always fled regardless of type of terrain. Young were less likely to survive encounters with coyotes than were adults, and no adult females were killed by coyotes. When types of terrain were pooled, females were more apt to flee than were males, but no difference existed in proportion of females and young that fled. When terrain type and sex of adults were pooled, no difference in survival existed between adults that fled and those that did not. When coyotes were encountered in open terrain, female mountain sheep fled more frequently than did female mule deer (Odocoileus hemionus). Ungulates less dependent on terrain for predator evasion than are mountain sheep may employ a more plastic strategy than artiodactyls inhabiting precipitous terrain.