The earliest customs service in the region began around eastward at St. Mary's Crossing on the
Saint Mary River in 1883, where the
North-West Mounted Police (NWMP) collected duties and patrolled the border. St. Mary's closed in 1901. At that time, the Cardston customs postal collecting station upgraded to a customs office, operating from 1901 until 1943. In 1904, the St. Mary's NWMP moved to Twin Lakes (present day
Police Outpost Provincial Park, about westward). Based about one mile north of border, the NWMP collected duties until a regular customs office opened, which operated from 1912 until 1932. The
Carway crossing was established in 1926 with the completion of the Cardston Highway. Canada Customs officer Herbert Legg created the name by combining the words Cardston and Highway. Prior to the erection of the building, a tent was used for four months. William Roberts was the inaugural customs officer from 1926 until 1938. The Port of Lethbridge provided administrative oversight. The customs building was replaced in 1954. In 1994, the border station hours were extended to match the 7am–11pm on the US side. ==US side==