The United States is an Arctic nation. Due to climate change, the Arctic is warming faster than any other region on Earth. As the loss of sea ice creates a more accessible Arctic, the nation must consider risks and opportunities for commerce and economic growth; security of our maritime domain; indigenous peoples and their subsistence cultures; and marine resource management, particularly along the Alaskan coast. To enhance Arctic marine transportation safety, protect Arctic people and the environment, build Arctic marine infrastructure, and to ensure safe and secure maritime shipping in the Arctic, Congress directed that the interagency Committee on Marine Transportation System (CMTS) coordinate the establishment of domestic transportation policies in the Arctic. This book answers that Congressional directive while addressing the considerations outlined above. This book also discusses current commercial maritime activity in the U.S. Arctic and anticipated activity in the next 10 years; actions taken by government entities in support of planning and developing U.S. Arctic maritime infrastructure; and federal interagency efforts to identify and prioritize Arctic maritime-infrastructure investments.