Route 28 Alton-Ossipee

[gokart-mozart]

I am seeking information about when and how NH 28 acquired its current alignment. I remember as a boy driving up along Alton Bay and past Roberts Cove on then-Route 28, buy the time I was driving (1966) the present alignment was in place.

Driving from North Wolfeboro to Ossipee, there is a parallel road called "Old Route 28" which appears and disappears in discontinuous segments.

Is there a history of this road anywhere?