 The closure of several smaller mills in Darrington and surrounding communities, including four for cedar shakes, caused the area's population to decline further in the 1960s and 1970s.Restrictions for logging on federal lands were further tightened in the 1980s and 1990s to protect the mountain habitats of threatened and endangered species, including the northern spotted owl, and caused further declines in the timber industries of the Darrington area.In response, Summit transitioned to processing private forests and lands managed by the Washington State Department of Natural Resources, maintaining its position as the town's largest employer.