Inspired by Garrett Fuller I decided to take a trip out to one of the few AT&T Long Lines sites that is still "active" today. When I set out, I was uncertain about the site's status and eager to uncover its secrets.
Long Lines History
For those unfamiliar with AT&T Long Lines, it was a groundbreaking network of thousands of microwave radio towers that spanned the United States. Beginning in the 1950s, this system formed the backbone of AT&T's long-distance telephone network, handling millions of calls daily.
Some of these sites played a crucial role beyond civilian communication. The AUTOVON (Automatic Voice Network) was a military telephone system that carried the nation's most critical military communications during the Cold War. This led to the construction of many sites designed to withstand nuclear blasts.
Even fewer of these sites were configured to carry Echo Fox/Combat Ciders? a communication network for Operation Looking Glass and Air Force One. The Hillsboro, MO site was unique in that it carried not only normal Long Lines Traffic but also AUTOVON and Echo Fox Traffic, one of only about 30 total.
Hillsboro, MO Long Lines Site
In August, I visited the Hillsboro site, located on what is now Old State Route 21. The imposing towers are visible from miles away. As you approach, there's an open driveway leading to a parking lot where I spotted several modern AT&T vehicles. Respecting the site's active status, I didn't venture beyond the gate or into the employee parking area. The main building is an impressive structure, reportedly extending several stories underground. This subterranean complex includes a bunker designed to automatically detect and withstand a nuclear blast. Fred Wall, a former Long Lines employee, shared that this site once required a staff of 65 to maintain and manage its operations.
Present Day Use by AT&T?
According to an archive of Long Lines historian Mark Foster, the Hillsboro facility has evolved with the times. It's current role has shifted to serve as a major fiber junction and houses a 4ESS toll switch. The once-critical microwave radios and AUTOVON switches have long since been decommissioned, though the exact date of their shutdown remains unknown.
Photos
Up close of the tower from the driveway. 
Two Towers from Old 21. 
Side of building from Old 21. 
Modern AT&T signage.
More
While the site's role has changed, its historical significance remains. These Long Lines facilities represent a crucial chapter in the development of America's communications infrastructure and played a vital role in national security during the Cold War era.
Additional photos and information about the Hillsboro site can be found on the Long Lines map and information site here.
All photos taken by me on August 1st 2024. Please feel free to reuse or redistribue