Portal is a city in Burke County, North Dakota, United States. The population was 125 at the 2020 census. Portal was founded in 1893. …Portal is a city in Burke County, North Dakota, United States. The population was 125 at the 2020 census. Portal was founded in 1893. Portal sits along the Canada–United States border and is a major port of entry border crossing for road and rail traffic. North Portal, Saskatchewan is just over the border north of Portal. It is one of three year-round, 24-hour ports in North Dakota.