original vintage single-sided black and yellow enameled heavy die cut circular advanced warning railroad crossing sign. features the large central black "x" with the letter r in two of the quadrants. the advance warning sign is usually the first sign you see when approaching a highway-rail intersection. the warning sign advises you to slow down, look and listen for a train, and be prepared to stop if a train is approaching. measures 30 inches in diameter. likely fabricated by the stonehouse sign co, denver, co.