This 610 mm narrow gauge 0-4-4T locomotive was built in 1912 by Vulcan Iron Works, for the Monson Railroad in Maine. It is now operated by Maine Narrow Gauge Railroad Co. & Museum (MNGRR) as locomotive #3 in Portland, ME with special trains on a ~2 km-long railroad running along the Eeastern Promenade in Portland.
More details are available here:
https://en.wikipedia.org/wiki/Maine_Narrow_Gauge_Railroad_Museum