The meridian 110° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole.
In Canada, the meridian forms the boundary between Nunavut and the Northwest Territories north of the parallel 70° north. Originally 110°W was intended as the Fourth Meridian for the Dominion Land Survey, but because of the imperfect surveying methods of the time, the meridian was placed a few hundred metres west of this longitude. The Fourth Meridian has been the entire boundary between Alberta and Saskatchewan since 1905.
From pole to pole
Co-ordinates Country, territory or sea Notes Arctic Ocean Canada Northwest Territories / Nunavut border — Borden Island Wilkins Strait Canada Northwest Territories / Nunavut border — Mackenzie King Island Unnamed waterbody Canada Northwest Territories / Nunavut border — Melville Island Eldridge Bay Canada Northwest Territories / Nunavut border — Melville Island (for about 2 km) Sabine Bay Canada Northwest Territories / Nunavut border — Melville Island Parry Channel Viscount Melville Sound Canada Northwest Territories / Nunavut border — Victoria Island
Nunavut — from on Victoria Island
Coronation Gulf Canada Nunavut — Jameson Islands and the mainland
Northwest Territories — from , passing through the Great Slave Lake
Saskatchewan — from , passing through Lake Athabasca, around 400m east of the Alberta border
United States Montana
Wyoming — from
Utah — from
Arizona — from
Mexico Sonora — passing just west of Ciudad Obregón at Gulf of California Mexico Baja California Sur Pacific Ocean Southern Ocean Antarctica Unclaimed territory — passing through the Walgreen Coast of Marie Byrd Land