Canada has announced Electronic travel authorization exemption for lawful permanent residents of U.S.A

Lawful permanent residents (LPRs), also known as “green card” holders, are non-citizens who are lawfully authorized to live permanently within the United States.

ETA exemption for lawful permanent residents of the United States is available to those who hold valid status in the U.S only.

These individuals must carry official proof of their status in the U.S. (or an equivalent status document) and a valid passport from their country of nationality (or an equivalent travel document) for all methods of travel to Canada.