The absence of snow between the rails would seem to indicate that some melting has occurred since the track was plowed. Even the flangers, with which the plows and some locomotives were equipped, would leave some snow behind.
There was indeed a lot of snow in those days. Enough that a passenger train was once snow bound for three days at a remote location. W.H.Eccles Heisler #3, in service today on the Sumpter Valley railroad, was one of the locomotives used in the relief train. Seven locomotives, from both SVRy and logging companies, were used to finally clear the line.