Crews at the Coast Guard Long Range Aids to Navigation stations, including the six Alaska-based stations, turned off domestic signals across the nation at 11 a.m. Monday.

The shutdown of the signal concludes the broadcast of the U.S. domestic signal. Stations Attu and Shoal Cove, which are bound by bi-lateral agreements with Russia and Canada, will continue to broadcast their international signals until later this year. All the stations will continue to be maintained and manned as the closure of the facilities proceeds over the coming months. Decommissioning dates have yet to be set and plans for the dismantlement of the stations are in development.

Loran-C was originally developed to provide radio-navigation service for U.S. coastal waters and was later expanded to include complete coverage of the continental U.S. as well as most of Alaska. Twenty-four U.S. Loran-C stations work in partnership with Canadian and Russian stations to provide coverage in Canadian waters and the Bering Sea. The system provided better than one-quarter nautical mile absolute accuracy for within the published areas and provided navigation, location, and timing services for both civil and military air, land and marine users. It was approved as an en route supplemental air navigation system for both Instrument flight rule and visual flight rule operations.

The Loran-C system served the 48 continental states, their coastal areas, parts of Alaska and neighboring countries. Coast Guard men and women run and maintained the Loran-C signal for 67 years, eight months and 24 days.