cross-posted from: https://lemm.ee/post/3141578
At the time of this photo, Union Pacific 3985, a Challenger class 4-6-6-4, was the largest operating steam locomotive in existence. This locomotive was donated by Union Pacific to a museum and has been replaced in excursion service by an even larger 4-8-8-4 Big Boy locomotive.
Photographed in September 2005 at the UP Albina Yard. Portland, Oregon.
3985 was donated to the Railroading Heritage of Midwest America (RRHMA), so it's no longer in UP's heritage fleet. The RRHMA is restoring it (when UP retired 3985 it had overdue maintenance). I don't know what RRHMA's plans for the loco are, but it's unlikely to be doing the kind of mainline tours that UP's Big Boy does.