This book integrates the results of Dr. Carol Johnston’s research on beaver ecosystem alteration at Voyageurs National Park, a mature beaver-altered landscape named after the French-Canadian voyageurs who transported packs of beaver pelts through the region more than 250 years ago. The text synthesizes information about the vegetation, soils, and chemistry of beaver impoundments, bridging the fields of ecosystem science and landscape ecology to analyze the dynamics of a beaver-altered landscape. The findings from this mature system can inform other scientists and managers about the sustainability and long-term ecosystem effects of beaver activity that is still expanding in much of North America. These findings are also compared to studies of beaver-occupied landscapes in other locations, including the Adirondacks, Tierra del Fuego, and other national parks.