Like those who kill elephants for their tusks, poachers in the national forests and parks in California cut the burls from centuries-old redwoods—the knotty growths that are so attractive and valuable to furniture makers and craftsmen but that are essential to the health of the trees. In their technique and style, Kirk Crippens and Gretchen LeMaistre’s beautiful and horrifying photographs consciously reference the work of 19th-century photographers whose images of Yosemite seemed to reveal a new Eden, and Ansel Adams, whose love of the region was manifest in both his photography and his tireless advocacy for conservation of the natural world.