Fifty-foot long concrete arrows top a ridge in the East Bay, greeting hikers who manage the steep climb to take in spectacular views but leave puzzled by the graffiti-covered work.
There’s no marker to explain that the arrows, originally painted bright yellow, played an important part in transcontinental aviation history. The arrows on Acalanes Ridge in Walnut Creek were part of a string of similar concrete devices that aided pilots who flew, as the saying went, “by the seat of their pants.” In those early days, there were few aviation charts so pilots had to use “dead reckoning” by following landmarks or railroad tracks.
According to a guide issued to pilots in 1921, Bay Area landmarks included Alcatraz Island, the Palace of Fine Arts Building in San Francisco and the 150-foot high Column of Progress, both holdovers from the 1915 World’s Fair. The San Francisco landing strip called Marina Field was three miles from the Golden Gate on the east side of the old fairgrounds.
The first coast-to-coast airmail route opened on Aug. 30, 1920, and by 1924 the line of giant concrete markers extended between Wyoming and Ohio. By 1929, the line stretched from California to New York with some of the arrows measuring 70 feet from end to end. Some histories report that the arrows were placed 10 miles apart, other estimates are as close as 5 miles. In all, there were 1,500 sites that, in addition to the arrows, were equipped with beacons and a maintenance shed.
In 1928, pilots received additional aid to navigating the Bay Area skies, although it was not an official part of the air mail system. In that year, Standard Oil placed a powerful light on Mount Diablo, one so strong it could be seen 150 miles at sea where the oil company’s tankers sailed.
The pioneering aviators included Grove Tyler, who was interviewed in 1944 and recalled how tough it was to bring the mail through.
“Seeing fellows go out and never come back, thinking all the time we could not continue,” said Tyler, who flew the San Francisco-Los Angeles route.
One of the original air mail pilots, he recounted that there was never enough money to cover expenses, and pilots often had to buy their own gear. Fellow aviator R. C. “Tex” Marshall, who flew the Reno-Salt Lake City-San Francisco leg of the U.S. Air Mail Service, said he flew no more than 200 feet or so above ground, navigating by landmarks.
“I found it was better to fly as close to the ground as possible,” Marshall wrote in his memoir.
The rotating, flashing beacons that guided the air mail pilots were mounted on a 50-foot high steel tower. The nearby shed housed a generator to power the rotating beacon. The beacon and shed at the Walnut Creek station are long gone and so is the tower that was torn down for scrap in World War II. The concrete arrows are all that remain.
According to Arrows Across America, a group that documents the arrow sites, there are actually two arrows that are joined together on Acalanes Ridge, which makes the site unique. The arrowheads point to locations in Concord while the shafts, or tails, point to Oakland and San Francisco. The tails of the arrows are uphill while the heads point downhill. Only the cement base that links the arrows is flat. It once held the tower for the beacon.
Advances in radio technology improved rapidly, making the arrows obsolete. There are still scores of the arrows left, largely ignored but occasionally literally stumbled on by hikers.
The Rear View Mirror by history columnist Jim Clifford appears in the Daily Journal every other Monday. Objects in The Mirror are closer than they appear.