SRI's mission is to preserve the knowledge, skills and technology involved with the maintenance and operation of steam locomotives, and to educate the public about the enormous impact these machines had in the economic development of Owosso, Michigan and the Great Lakes Region. The institute is home to the majestic Pere Marquette No. 1225, the largest operating system locomotive of its kind. Pere Marquette No. 1225 embodies the characteristics of the last and most powerful steam locomotives. The Steam Railroading Institute offers weekend excursions throughout the summer and several all day excursions throughout the year. The most popular of all excursions is the "North Pole Express," available during November and December.