Beaver (Castor canedensis), well known for their dam-building ecosystem engineering activities and potential as a nuisance species, are increasingly being used as a restoration agent and conservation tool to restore dynamism in streams and create better habitat for a variety of threatened biota. Beaver don’t build dams everywhere, but where they can, they are a potentially cheaper approach to restoring degraded stream habitats. Their dam building activity sets off a cascade of hydrologic, hydraulic and geomorphic feedbacks and provide a diverse array of ecosystem services. Examples of restoring streams with beaver will be shared that highlight how beaver can reconnect incised channels with their former floodplains, create better habitat for native fish, expand riparian areas into uplands, and invoke population level responses in salmon. Beyond that, a model that predicts the capacity of the landscape to support dam-building activity by beavers will be presented that helps build realistic expectations about where beaver may or may not be appropriate restoration agents. These examples will be brought together with some examples of new monitoring methods and modeling tools that help quantify and better elucidate these responses and plan and design restoration projects that exploit beaver.