Stock photography, photos: A muddy mountain biker Stock photos of A man covered with mud from mountain biking near Truckee, CA. Photograph: © William Stevenson Click for a larger image and more information Keywords associated with this stock photo: mountain biking, biking, cycling, bicycling, active, liveliness, adventure, freedom, enthusiasm, California, CA, white, green, muddy, dirty, filth, mud, dirt, vertical, Pres