All mountain skis are versatile skis that are designed to be used anywhere on the mountain, whether on groomers, bumps, in trees or open bowls, and -- depending on the ski --trips into the terrain park. "Narrow" All mountain skis range from 80mm to 94mm underfoot and are generally best suited for Eastern and Midwestern skiing, whereas Wide" All-mountain skis range from 95mm to 108mm and most appropriate for the range of conditions in the West. All mountains skis also range from lighter "playful" skis that are easy to pivot and jump with to "directional" skis that tend to be stiffer and heavier and are designed for stability at speed through variable snow. If you want a single pair of skis for a range of terrain and conditions, you will probably want an all-mountain ski. , An all mountain ski is versatile and built with a wide range of terrain in mind. 'All Mountain' encompasses all terrain on the mountain and often has a rocker/camber/rocker profile that helps with variable snow conditions and handling any terrain the mountain has to offer. , An All-Mountain ski is a pair of skis that are versatile in any terrain including groomed runs, moguls, trees, park and pipe, and even the backcountry. Most all-mountain skis are directional in shape but many brands have shifted to producing twin shaped making them even more versatile. All-mountain skis are what most skiers ride if not a part of one's quiver.