From Alaska to the Florida Keys and from northern Maine to Southern California, rivers have long played a central role in the lives of Americans—and in the health of flora, fauna, and habitat that make up thriving ecosystems. Today, many of these waterways are under assault from pollution, dams and other manmade barriers, and climate change. But there’s still time for policymakers to protect and restore our country’s rivers. Take our quiz to test your knowledge of U.S. rivers, and all the benefits they bring.