The Baltimore and Ohio Railroad Museum held it's annual Railfest Steam Days weekend on October 13th and 14th, 2012, affording museum patrons a rare opportunity to see the "William Mason" under steam. Patrons traveled along an old B&O ROW from Museum to an open field via the Museum's second operating steam engine, the No. 4, the St. Elizabeth, an 0-4-0 Saddle Tank Engine built in 1950 and known affectionately as "Little Lizzie". Lizzie is the last steam locomotive produced by the H.K. Porter Company of Pittsburgh, PA