Bay Circuit Trail: Callahan State Park.

Callahan State Park is like Borderlands in that it occupies two towns, Framingham and Marlborough.

The Bay Circuit Trail meets it coming in from the north after passing through the Sudbury Valley Trustees parcel called the Welch Reservation.

It is in two wings with the eastern section consisting of lowland terrain giving way to the western section hill called Gibbs Mountain.

The border between the two towns runs along Beebe Pond.

From there the trail passes through fine forests on its way to the Sudbury Reservoir.

It even encounters the street layout of a ghost subdivision.