The H.J. Andrews Experimental Forest is a slice of classic Oregon: due east of Eugene in the Cascade Mountains, it comprises 15,800 acres of the Lookout Creek watershed. The landscape is steep, with hills and deep valleys and cold, fast-running streams. The densely forested landscape includes cedar, hemlock, and moss-draped Douglas fir trees. One of eighty-one USDA experimental forests, the Andrews is administered cooperatively by the US Forest Service,...