All Over The Map: Searching for Washington’s lost Airway Beacons

Jun 24, 2022, 12:06 PM | Updated: Oct 25, 2022, 4:20 pm

If you know where to look – and are willing to undertake a little rock scramble – a hike in the Cascades goes right past the remnants of a once sprawling nationwide network of transportation infrastructure.

Admittedly, this opening line might make it sound like we’re talking about an artifact from the early days of railroad history – perhaps an old depot, or a roundhouse, or maybe a derelict caboose. But actually, this particular artifact relates to a form of transportation from a more recent era and at much higher altitudes than those traveled by an iron horse.

Brian Dirks lives in South King County. He’s in his early 60, and is retired from a long career in public sector communications. In his spare time, Dirks often visits trails around the area with his twin brother and some other friends as a part of a hiking group.

On a recent outing along the Easton Ridge Trail, on the east side of Snoqualmie Pass, Dirks saw something that caught his eye and ultimately sent him on a brief climb, and then what became a fruitful search for more information.

It was near the top of Easton Ridge, at about the 4,400-foot level, where Dirks first saw what he described as a “rock scramble.” Though he admits to being a little afraid of heights, when he noticed what appeared to be a large piece of milled lumber – perhaps a railroad tie – sticking out from the rocks, he decided to hoist himself up to take a closer look.

“At the top, I found a flattened area, and there were actually two of these railroad-tie looking things and they were spread out maybe six feet apart,” Dirks told KIRO Newsradio earlier this week. “And my first thought was that it was an old fire lookout station. Also, along the side of [the rock scramble] was some old corrugated sheet metal just kind of lying there in a heap.”

“So it kind of piqued my curiosity,” Dirks continued.

The discovery high atop Easton Ridge sent Dirks and his curiosity down a deep rabbit hole. With online searches and some critical help from the Museum of Flight Research Center, Dirks figured out that what he’d found wasn’t from the railroad or an old lookout tower. It turns out that those pieces of lumber are all that remains of the base of what used to be an airway beacon tower – a tall, skinny structure that was once part of a network of markings and lights designed to give early aviators a way to visually follow marked routes between population centers all over the country.

The routes were part of what was essentially a national interstate highway in the sky called the Transcontinental Airway, and the Easton Ridge tower helped mark the path through the Cascades for aircraft flying between Seattle and Helena, Montana.

Civil aviation boomed in the years after World War I, and the first towers in the system started going up in the 1920s– many along official airmail routes – in the earliest years of aviators moving written correspondence between American mailboxes at previously unheard-of speeds. Airmail routes and the airway beacon towers were even honored on a 1928 five-cent air mail U.S. postage stamp which depicted an iconic beacon tower along an airway route in Wyoming.

Around the same time that the federal government was marking air mail routes, private oil companies – with government blessing – began creating their own system of “daylight signals” – such as big concrete arrows on the ground, and names of towns (with directional arrows) painted on the roofs of buildings.

In California, Standard Oil built at least two massive beacon towers in the Los Angeles area. Meanwhile, competitor Richfield Oil made plans to build a series of towers from the Mexican border to the Canadian border adjacent to what were to be grand Richfield service stations. Apparently, those plans were dashed by the stock market crash in 1929 and the ensuing Great Depression; some towers were built in California, but none in Oregon or Washington. However, there was at least one “Beacon” service station built in Seattle with a decorative beacon that may have been a nod to the real ones, and an official Commerce Department airway beacon installed downtown atop the Northern Life Tower.

Brian Dirks says that the particular tower he found on Easton Ridge likely dates to 1935 – based on some old aviation charts shared by the Museum of Flight, and an old photo he tracked down that might have been taken when construction was finished.

According to Dirks’ research, the tower on Easton Ridge was metal, and was probably about 30 feet tall. It had a blinking light on top which was made from a giant lens in a housing which was illuminated using acetylene gas – like that used in a welding torch – which burned 24 hours a day, since there wasn’t a human on-site to turn it on at sunset and turn it off at sunrise. This was a bright light which was meant to be seen, with an estimated strength of 2,000,000 candle power.

The acetylene was stored in a small metal shed at the base of the tower, probably in a tank or series of tanks, which contained enough gas to fuel the flame for up to six months. How a gas flame was made to blink is unclear, but one guess is that the beacon used an oscillating valve like what might be found on a sprinkler; that is, the gas pressure caused a “gate” to swing back and forth to vary the gas supply so that the flame would appear to blink, but would not be extinguished. The gas-powered flames were typically only used in remote areas where electricity wasn’t readily available.

Queried about the towers, local aviation historian Lee Corbin told KIRO Newsradio in an email that he’d been researching the whereabouts and history of specific towers in Washington for many years. He also tracked down some early 20th century materials describing the “Flasher Mechanism” used in lighted maritime buoys which may have also been used in airway beacons.

“The flasher regulator assembly serves a double purpose of reducing the gas pressure present in the storage cylinders to a pressure of about 100mm of water,” the old literature reads, “and releasing the gas to the burners in puffs which correspond to the flashes of light.”

The acetylene gas, Corbin says, was created from mixing calcium carbide with water – just like an old miner’s headlamp, but on a much larger and much brighter scale.

Like those old miner’s headlamps, airway beacons become obsolete, too. The need for lighted beacons was gradually diminished by the rise of radio navigation, which was already in use in many areas by the late 1930s. Still, many of the towers remained in place, and it wasn’t until early 1965 that the Federal Aviation Administration took steps to decommission – but not necessarily remove – the bulk of those that remained.

According to the website Arrows Across America, just one concrete arrow and 17 beacon towers remain in the Evergreen State, including notable examples in Toledo, Washington and on Kachess Ridge, which is not far from Easton Ridge, and is accessible via Kachess Ridge Trail.

If you go, keep your eyes peeled. Along with the airway beacons, there might still be some undiscovered traces of railroad history or old fire lookouts just waiting to be found. I’m standing by for your email.

You can hear Feliks every Wednesday and Friday morning on Seattle’s Morning News with Dave Ross and Colleen O’Brien, read more from him here, and subscribe to The Resident Historian Podcast here. If you have a story idea, please email Feliks here.

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All Over The Map: Searching for Washington’s lost Airway Beacons