QUOTE: Originally posted by bwilcox SD70M's were re-numbered UP 3975-3999. Also check the following links: http://www.uphs.org/locorostjune1997.htm http://utahrails.net/all-time/all-time-61.php http://utahrails.net/all-time/up-x-sp-index.php As always, google.com will guide you towards this information, just be creative with your search requests. The above info and links took me less than 5 minutes to find.