The book "Boys Motorists on the Plains; or, Guardian of the Lost Lake" by the author Clarence Young tells about the exciting adventures of three friends - Jerry, Bob and Fred, who go on a journey across the boundless prairies, where dangers and mysteries await them. During their journey, the boys encounter the mysterious guardian of the lost lake, who has hidden himself from the world and keeps many secrets. Will the boys be able to solve the riddles about the local Indians, save their friend from danger and restore peace in this mysterious area? Readers are waiting for an exciting story about friendship, courage and loyalty, which will captivate every fan of adventure novels.