Photo taken by Chester Gehman in January 2016
BH Photo #345106
My guess would be the flood of March, 1936 took out the prior bridge. One of the worst floods in the history of Vermont, Massachusetts, and Connecticut.
Looks like it's been a footbridge since at least the 1940s; the road connection is severed in between the 1941 (1936 survey) and 1947 (1945 survey) topos.