The current, iconic Great Lakes pine forests of Minnesota, Wisconsin, and upper Michigan are greatly simplified in composition and structure compared to their historical equivalents from the late 1800s. Forests that were composed of mixtures of red pine, eastern white pine, jack pine, and many hardwood species are now dominated by red pine alone or have been converted to aspen or oak. Moreover, these new forests often have simplified age structures, occurring now as plantations or even-aged natural-origin stands. Forest Service scientists, working with researchers from the University of Minnesota, Iowa State University, and Michigan Technological University, and managers on the Chippewa National Forest began a large-scale experiment to restore structural complexity and tree species diversity in simplified forests using a natural models approach. Although red pine is still the dominant tree, these forests now support a diversity of species in several age cohorts, within structurally complex stands. While the historical condition is the reference condition for this restoration effort, these forests are better positioned to adapt to future threats, including climate change-induced decline of red pine and native and non-native pests. This project serves as an example of restoration that can position forests to adapt to an uncertain future by learning from their past.