You’ll find them in a nearly straight line between the East Coast (New York) and the West Coast (San Francisco). Like an ancient cosmic map, they are spaced about 15 miles apart and placed on any available surface – the side of a mountain, across the desert floor, and in the great, flat plains of the central United States – anywhere where they can be easily seen from space. Although many are now covered with scrub brush, these giant concrete arrows, sometimes as much as 70 feet in length, leave backpackers and hikers who stumble across them scratching their heads. What are they? Where did they come from? Who scattered them across the USA?
The giant arrows are remnants of the Transcontinental Airmail Route, a sequence of sequentially lighted beacons and giant arrows funded by Congress in 1923 to aid pilots navigating across the United States. Prior to their construction, pilots navigated across the country by picking their way from visible landmark to visible landmark, a method that proved troublesome in vast areas of empty, repetitive desert or remote mountainous regions. The job proved dangerous with nearly 1 in 10 early airmail pilots dying in plane crashes. Thus, the lighted airway beacons were a significant aid to pilots in an era before radio navigation was possible.
The transcontinental airmail stations consisted of huge rotating beacons mounted on 53-foot towers and spaced ten miles apart. Most of the facilities used huge bright-yellow concrete arrows pointing in the direction of the next tower. The beacons themselves flashed a code to identify each beacon’s unique identification number. When visibility was good, light from the next beacon could be seen by the pilot. Each arrow pointed to the next station, a feature that helped keep pilots on course if weather obscured the light from the next lit beacon.The first segment of the Transcontinental Airmail Route was built between Chicago and Cheyenne, Wyoming. By the end of 1925, the 2,665-mile lighted airway between New York and San Francisco was completed. By 1927, the lighted airway between New York and Salt Lake City, Lost Angeles to Las Vegas, Los Angeles to San Francisco, New York to Atlanta, and Chicago to Dallas (4,121 miles in total) was completed. By 1933, the Transcontinental Airway System totaled 1,500 beacons covering 18,000 miles. However, their usefulness quickly faded.
By the end of the 1930’s, radio guidance and radar helped eliminate the need for the beacons and thus, during World War II, many of the beacon towers were removed to prevent aiding enemy bombers in navigation. However, hundreds of the giant arrows remain scattered across the United States leaving bewildered backpackers to find the remnants of the long-gone, marvelous highway of light.
Example NGS data sheet for a Transcontinental Airway Beacon
Many people make a hobby of hunting for and finding these long-lost beacons. Below is a NGS datasheet documenting the location of one of the beacon towers and arrow.
The NGS Data Sheet
PROGRAM = datasheet95, VERSION = 8.9 1 National Geodetic Survey, Retrieval Date = JUNE 7, 2016 BU1878 *********************************************************************** BU1878 DESIGNATION - BEACON 24 GREEN AIRWAY 6 BU1878 PID - BU1878 BU1878 STATE/COUNTY- AL/BUTLER BU1878 COUNTRY - US BU1878 USGS QUAD - GREENVILLE WEST (1986) BU1878 BU1878 *CURRENT SURVEY CONTROL BU1878 ______________________________________________________________________ BU1878* NAD 83(1992) POSITION- 31 51 09.39294(N) 086 43 07.24101(W) ADJUSTED BU1878* NAVD 88 ORTHO HEIGHT - **(meters) **(feet) BU1878 ______________________________________________________________________ BU1878 LAPLACE CORR - 1.07 (seconds) DEFLEC12B BU1878 GEOID HEIGHT - -27.430 (meters) GEOID12B BU1878 HORZ ORDER - THIRD BU1878 BU1878.The horizontal coordinates were established by classical geodetic methods BU1878.and adjusted by the National Geodetic Survey in December 1992. BU1878. BU1878.Significant digits in the geoid height do not necessarily reflect accuracy. BU1878.GEOID12B height accuracy estimate available here. BU1878 BU1878.The Laplace correction was computed from DEFLEC12B derived deflections. BU1878 BU1878. The following values were computed from the NAD 83(1992) position. BU1878 BU1878; North East Units Scale Factor Converg. BU1878;SPC AL W - 205,647.911 673,943.519 MT 1.00000074 +0 24 44.5 BU1878;UTM 16 - 3,524,133.202 526,614.828 MT 0.99960874 +0 08 54.5 BU1878 BU1878 SUPERSEDED SURVEY CONTROL BU1878 BU1878 NAD 83(1986)- 31 51 09.40081(N) 086 43 07.22639(W) AD( ) 3 BU1878 NAD 27 - 31 51 08.85900(N) 086 43 07.30900(W) AD( ) 3 BU1878 BU1878.Superseded values are not recommended for survey control. BU1878 BU1878.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums. BU1878.See file dsdata.txt to determine how the superseded data were derived. BU1878 BU1878_U.S. NATIONAL GRID SPATIAL ADDRESS: 16REA2661424133(NAD 83) BU1878 BU1878_MARKER: 22 = AIRWAY BEACON BU1878 BU1878 HISTORY - Date Condition Report By BU1878 HISTORY - 1944 FIRST OBSERVED CGS BU1878 BU1878 STATION DESCRIPTION BU1878 BU1878'DESCRIBED BY COAST AND GEODETIC SURVEY 1944 (FN) BU1878'STATION IS BEACON 24 ON GREEN AIRWAY 6 BETWEEN MONTGOMERY AND BU1878'MOBILE. IT IS LOCATED ON THE W SIDE OF THE GREENVILLE AIRPORT BU1878'ABOUT 6 MILES WNW OF THE CITY OF GREENVILLE. IT IS A REVOLVING BU1878'BEACON OF THE STANDARD TYPE WITH FIXED GREEN LIGHTS THAT SHOW BU1878'ALONG THE COURSE. IT IS SUPPORTED ATOP A FOUR-LEGGED STEEL BU1878'STRUCTURE, PAINTED RED AND WHITE, AND ABOUT 60 FEET HIGH. BU1878' BU1878'THE CENTER OF THE REVOLVING LIGHT WAS THE POINT OBSERVED. THE BU1878'GREEN LIGHTS FLASH THE CODE LETTER H (....). *** retrieval complete. Elapsed Time = 00:00:04
List of known Transcontinental Airmail Route beacons/arrows
Should you wish to witness these arrows yourself, you may view a complete list of known locations of Transcontinental Airmail Route beacons and concrete arrows here. The list contains the station name, county, and GPS coordinates of the site.
Image CreditsTranscontinental Air Mail Route Beacon 37A concreate arrow via Wikipedia Commons with usage type - Creative Commons License
First Transcontinental Air Mail Route involving both day and night flying opened July 1, 1924. via Wikipedia Commons with usage type - Public Domain
Beacon and Wind-Driven electric generating set via University of Wisconsin with usage type - Public Domain
Beacons from the 1924 Aircraft Year Book via 1924 Aircraft Year Book with usage type - Public Domain
Concrete Arrows and the U.S. Airmail Beacon System via Altered Dimensions