43˚ 47’ 31” N, 110˚ 08’ 11” W This is a tree that David Gonzales calls “the Fighter.” It’s rooted in the loamy soil of a high mountain pass in western Wyoming, poised at the edge of a clearing beneath a sheer volcanic scarp that locals call the Breccia Cliffs. In the summer, downy gray Clark’s nutcrackershop purposefully among its branches. Elk bed down beneath it in the fall. Come winter, the frozen footprints of foxes and ermine speckle the snowfall around its trunk. But unlike these animals, the flitty faux-jays and the migrating elk, the Fighter itself is stoic, unmoving. Archimedean, even. Its position on this earth is fixed.The Fighter is a whitebark pine, a high-elevation species of five-needle conifer that’s mostly known these days for the trouble it’s in. Throughout the northern Rockies, entire forests of whitebark are being wiped out by a pair of complementary afflictions: white pine blister rust, an invasive fungal disease that causes branches to swell...