That locomotive is operational at the Mt. Rainier Scenic Railroad.
Mt. Rainier Scenic Railroad
I've ridden behind this engine. They were calling it a Porter then, but it's now listed on their redesigned website (a regression from the old one), as an Alco. I don't know.
Beautiful ride, with a combination of closed and open cars. Loop turnaround by a lake, with time for picnicking. Also, in good weather (which we had), stunning views of Mt. Rainier. The railway is in the boonies, about a 1.5 hour drive from Seattle.
For those in the Pacific Northwest, or who are visiting, I highly recommend taking the time and making the effort to experience this magnificent little railroad.
But call ahead to see what's gonna be running. First time we went, when we showed up there was a sign saying "We are having a diesel day." Bitterly disappointed, and didn't wanna go, but family insisted that we ride anyway. EDIT: Great as the scenery is, I was there for the steam action.
The second try was a 4th of July special, with a catered cookout by the lake. Figured they wouldn't DARE run a diesel for that, so purchased tickets in advance online. It wasn't until they were riding behind No. 17 that my family fully understood why I had been so angry about the diesel.
The current website describes a different turning procedure than we experienced (I think 4 years ago), and explains why.