A key theme among seminal contributions to policy studies, including Baumgartner and Jones (1993; 2002), Sabatier and Jenkins-Smith (1993), and Hall (1989; 1993), is that “external perturbations” outside of the policy subsystem, characterized by some type of societal upheaval, are critical for explaining the development of profound and durable policy changes which are otherwise prevented by institutional stability. We argue that these assumptions, while useful for assessing many cases of policy change, do not adequately capture historical patterns of forest policy development in the U.S. Pacific Northwest. Differences in policy development concerning state and federal regulation of private and public forest lands governing the same problem, region, and population challenge much of the prevailing orthodoxy on policy dynamics. To address this puzzle, we revisit and expand existing taxonomies identifying the levels and processes of change that policies undergo. This exercise reveals the existence of a “thermostatic” institutional setting governing policy development on federal lands that was absent in the institutions governing private lands. This thermostatic institutional arrangement contained durable policy objectives that required policy settings to undergo major change in order to maintain the institution's defining characteristics. Policy scientists need to distinguish such “hard institutions” that necessitate paradigmatic changes in policy settings from those that do not permit them.