Stock photography, photos: Two muddy men mountain biking Stock photos of Two men covered with mud while mountain biking and racing near Truckee, CA. Photograph: © William Stevenson Click for a larger image and more information Keywords associated with this stock photo: mountain biking, bike, cycling, bicycling, biking, bicycle, single track, training, fast, action, active, effort, energy, liveliness, speed, perseverance, endurance, enduring, determination, momentum, motivation, strength, strong, power, aerobic, challenge, desire, difficult, adventure, freedom, enthusiasm, fastest, fast, speed, success, winning, youth, risk, danger, spring, summer, California, CA, white, green, competition, compete, muddy, dirty, filth, mud, dirt, outdoor, outdoors, outdoorsman, outside, sports, sport, sportsman, recreation, recreational, exercise, exercising, physical fitness, health, healthy, two, 2, people, 20s, twenties, exciting, excite, adrenalin, thrill, thrilling, athlete, athletic, horizontal, Pres, Kram