120th meridian west
The meridian 120° 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.
The mean solar time at this meridian determines the time for the Pacific Time Zone (UTC−08:00) during standard time. Most of the year however, it is the meridian for Alaska Daylight Time, as daylight saving time is observed for nearly 2/3 of the year.
From Pole to Pole 
Co-ordinates Country, territory or sea Notes Arctic Ocean Canada Northwest Territories — Prince Patrick Island M'Clure Strait Canada Northwest Territories — Banks Island Prince of Wales Strait Amundsen Gulf Canada Nunavut
Northwest Territories — passing through Great Bear Lake
British Columbia / Alberta border — from
British Columbia — from Intersection Mountain at ; at this point the meridian meets the Continental Divide, and the boundary with Alberta diverts southeast
United States Washington
Oregon — from
California / Nevada border (approximate) — from
California — from
Pacific Ocean Santa Barbara Channel United States California — Santa Rosa Island Pacific Ocean Southern Ocean Antarctica Unclaimed territory
See also