This past Friday I talked on the phone with Brian Kahn, the host of “Home Ground” on Montana Public Radio, about my forthcoming book, The Spine of the Continent. Kahn was doing a bit of leg work in advance of having me on his show; an attorney and former head of the Montana Nature Conservancy, he addresses environmental issues but is keenly aware that much of his listening audience is inclined against the very term. I explained that The Spine of the Continent (Lyons Press,