Stock photography, photos: Two men mountain biking Stock photos of Two men mountain biking on a dusty Donner Summit, CA. Photograph: © William Stevenson Click for a larger image and more information Keywords associated with this stock photo: biking, mountain biking, bike, cycling, bicycling, back country, active, dirt, dry, dust, dusty, aerobic, momentum, desire, difficult, starburst, sunburst, adventure, freedom, fast, speed, blur, man, male, men, together, partners, team, trail, summer, vertical, California, sierras, evening, morning, Waye, Schi, Outdoor, outdoors, outside, sports, sporting, sport, exercise, physical, fitness, outdoorsman, sportsman, adult, young, adventure, adventuring, twenties, 20, s, 30, thirties, two, 2, people, cycle, cyclers,