I'll take a lengthy stab here. Pretty sure this is at Erving looking east, photographer being a little bit east of where the dirt truck parking area is today. Not sure if there used to be a tower or office in that location, looks like some kind of shadow on the ground in Google maps.
Let's break down the image. Simply put this is a sweeping right-hand curve with the tracks between the road and the river.
- In the image the curve of the tracks at least 60 degrees or so.
The photographer appears to be standing at the start of the curve.
The river is relatively narrow and appears to enter a rapid in the curve.
The river is tight against the tracks with rock close to the photographer and begins to separate as you progress away with foliage.
The road on the left has guard rails or guard wires, indicating it is a likely more significant road.
The road is turning back toward the photographer based on the change in spacing of the guardrail at the far left edge.
The road continues relatively straight in the distance, dipping and then climbing a bit.
There is a sizeable elevation difference between the road and the tracks, with little room for anything to be constructed between.
There is no other railroad infrastructure other than the poles (no bridges).
I can rule out Pownal (looking east) because the spacing between the tracks and the river is pretty uniform in the curve. Also the vertical change between road and rails is not quite the same as the photograph. The topography is just not the same.
Zoar/Charlemont have a few different options, but S. River Rd/Charlemont Rd stay pretty uniform to the tracks. There's one a little further west on Zoar Rd (looking east) but it includes bridge infrastructure and doesn't have the same rocky lining between the track and river.