The Aquatic Conservation Strategy (ACS) of the Northwest Forest Plan guides management of riparian and aquatic ecosystems on federal lands in western Oregon, western Washington, and northern California. Since its application in 1994, many federal lands have applied a precautionary approach to aquatic management by applying interim riparian reserve boundaries, or have had conservative management within interim riparian reserves. Forest Service scientists applied new scientific findings and tools to evaluate two potential options. These options are examples of potential ways to meet ACS while meeting other management goals, such as timber production, and challenges, such as emerging concerns about climate change. Specifically, based on simulations: (1) about 76 percent under option A and 72 percent under option B remain solely devoted to ACS goals; (2) 15 percent under option A and 19 percent under option B should be able to meet ACS goals and also contribute toward goals such as timber production; and (3) 9 percent would be returned to general management (matrix lands). A large percentage of streams with high ecological sensitivity occurred on nonfederal lands, a circumstance that merits further analysis in the context of landscape-scale considerations for biodiversity and recovery of species listed under the Endangered Species Act. Information needs remain with regard to the application and effectiveness of these options, and an adaptive management context is critical for continued improvement.