As he wrote "Who is", it seems as though it still exists. But in what form? Active? Static display? It is not 261 and that Group. It does not look like UP 844. It is not SP 4449, which is I believe still actually owned by the City of Portland, OR.
Hmm. Well, I am lost here. The apparent pilot side mounted air pumps is not registering. It is not MILW. It is not SP&S. It is not NP, nor GN. Not SP that I can place. Not UP. D&RGW 4-8-4 pumps were boiler side mounts. I've got to now guess AT&SF?
Union Pacific, FEF-1. It's #806 http://www.steamlocomotive.com/northern/up806.jpg But Fitz gets the prize--Good eyes, Jim!