Stock photography, photos: A couple hiking uphill on skis. Stock photos of A couple hiking uphill on skis. Photograph: © William Stevenson Click for a larger image and more information Keywords associated with this stock photo: skiing, ski, skiers, snow, winter, climbing, sierra, mountains, california, ca, cold, endurance, aerobic, strong, strength, hiking, difficult, back country, high country, alpine, determination, touring, vertical, Outdoor, outdoors, outside, sports, sporting, sport, exercise, physical, fitness, outdoorsman, sportsman, adult, young, adventure, adventuring, twenties, 20, s, 30, thirties, two, 2, people, climb, climbers, hike, hiking, hikers, ascend, ascending, bens, kenn