Update:
We stayed at West Glacier RV park (on the other side of the railway Bridge going into Glacier NP 1st week of July 2020.
We are 13'4" hitched.
I had DW stand on the walkway on the right as I crept under the bridge.
We made it with inches to spare.
As far as the park goes...
Kinda plane. Its new. Takes a long time to grow trees. Very clean, well kept. Very friendly and helpful staff. Walking distance to WG village.
GNP is right there. When we were there Going to the sun road was closed at Logans pass due to snow. We took a drive up to the Canadian boarder. Very scenic. Also took a float trip.
Will definitely do this again