The Minneapolis & St. Louis used Mikados in pre-diesel days to speed its bridge traffic between eastern and western connections. No. 604, shown here in a photo acquired via eBay, belonged to the M&StL's first group of class M1 2-8-2s built in 1915 by the American Locomotive Company. Specifications for this earlier group of the M1 class were similar to those for No. 629 and 631 following, except that this group had a lower boiler pressure of 185 p.s.i., produced 46,056 pounds of tractive effort, and weighed 259,900 pounds. The date, location, and the photographer's identity for this photo are unknown.