Where are the US customs and border crossing locations in Maine?

In Maine, U.S. Customs and Border Protection (CBP) has several border crossing locations. The primary crossings include the Houlton Port of Entry, which connects with Canada via Route 1, and the Calais Port of Entry, which is near the New Brunswick border. Additionally, there are crossings at Madawaska and Fort Kent. These locations facilitate customs processing for travelers and goods entering the United States from Canada.