From Boston

North on I-93 past Franconia Notch, exit 35 to Route 3 North to Pittsburg

From Connecticut:

North on I-91 to St. Johnsbury, VT then Route 2 East, to Lancaster, NH then to Route 3 North to Pittsburg

From Portland ME: 

Maine Turnpike North to exit 11, then Route 26 to Colebrook, NH and Route 3 North to Pittsburg

From Montreal:

East on 10 to Magog, South on 55 to Newport, VT, then 11 east to Route 114 North to West Stewartstown, NH on Route 3 North to Pittsburg