Transcontinental Airway System

The lighted airway was proposed by National Advisory Committee for Aeronautics (NACA), and deployed by the Department of Commerce.

It was situated in the middle of the airmail route to enable aircraft to depart from either coast in the daytime, and reach the lighted airway by nightfall.

[1] By the end of the year, the public anticipated anchored lighted airways across the Atlantic, Pacific, and to China.

24 inches (610 mm) diameter rotating beacons were mounted on 53-foot (16 m) high towers, and spaced ten miles apart.

The sequence was "WUVHRKDBGM", which prompted the mnemonic "When Undertaking Very Hard Routes Keep Directions By Good Methods".

Many arrow markings were removed during World War II, to prevent aiding enemy bombers in navigation.

The 1924 U.S. Air mail route
1928 Commemorative Beacon on Sherman Hill
Light, tower, shed, and concrete arrow
These are the remnants of Transcontinental Air Mail Route Beacon 37A, which was located atop a bluff in St. George, Utah, U.S.A. With concrete arrows indicating the direction to the next beacon, a rotating light tower, and a shed that usually held a generator and fuel tanks, these beacons were once situated every 10 miles on air routes across the United States beginning around 1923.
A former concrete arrow of the Transcontinental Airway System in Walnut Creek in August 2018
Beacon 61B on a modern display tower, originally installed on route CAM-8 near Castle Rock, WA