“Motorcycle Boys Over Rocky; or, The Mystery of the Air" - an exciting adventure novel from the popular writer Clarence Young. In this book, the young heroes once again find themselves in the middle of an incredible adventure when their journey along the Rocky Mountains turns into an exciting challenge. Aviation races, mysterious crimes and incredible trials - all this awaits the heroes of this exciting book. Will the Biker Boys be able to overcome all the obstacles and reveal the secret of the air? Find out, see for yourself and feel the real atmosphere of exciting adventures in the extraordinary novel "Motorcycle boys over Rocky; or, The mystery of the air"!