This morning, a reader phoned to say that he didn't think the red line marked an alternative route for the power lines. Rather the map had been created by someone who was part of Farmers and Families for Livingston, who was working on a inventory of National Register listed and eligible properties within three miles of the proposed route. The suggestion was that the red line on the map marked three miles west of the route, which presumably is the solid black line at the right.
This afternoon, another reader provided the link to a map published by New York Transco, a collaboration of New York transmission owners, among them National Grid. The map, which runs for several pages and purports to show the proposed route of the power lines through Columbia and Dutchess counties, can be accessed here.