Sumas (SOO-mas) is a city in Whatcom County, Washington, United States.

The Sumas–Huntingdon port of entry at the north end of State Route 9 operates 24 hours a day.

The area was home to the Nooksack Indians in the millennia prior to the arrival of the first permanent settler Robert Johnson in 1872.

[4] It was called "Sumas" meaning "land without trees"[4] or "big flat opening.

[6][4] Originally called "Sumas City,"[4] the town was officially incorporated on June 18, 1891.

"[4] The area around Sumas drains into the Fraser River in Canada, in a broad floodplain.

Approximately 85 percent of homes in the city were damaged and hundreds of residents were rescued after a partial evacuation.

[10] According to the United States Census Bureau, the city has a total area of 1.48 square miles (3.83 km2), all of it land.

[11] Because of the limits of technology when the border with Canada was surveyed, the border west of the Cascade Range lies above the 49th parallel; the most extreme offset (three city blocks) is at Sumas, which is thus the northernmost incorporated place in the contiguous United States.

The City of Sumas provides electricity to residents and businesses purchased from the Bonneville Power Administration, as well as offering water, sewer, and analog cable service including a mix of major Seattle networks, Canadian broadcast TV, expanded cable channels, and Showtime.