Pipes, Passageways, and Prohibition: Flagstaff’s Underground Story
Under the streets of modern-day Flagstaff lies a network of forgotten utility corridors, rumored Prohibition routes, and stories tied to early immigrant labor. While many passages have been sealed or obscured by modern development, the legacy of what once ran beneath the city remains a compelling part of Arizona’s past. What are the underground tunnels in Flagstaff, and what were they used for?
Utility Tunnels
Initially, the tunnels served as a series of underground utility tunnels linking key buildings. It is unclear when they were first constructed, but in the 1920's the passages carried steam, water lines, heating systems, and electrical conduits between hotels, government offices, and commercial structures.
The tunnels were wide and tall enough for people to fit through, allowing maintenance on pipes and lines to be done very easily. However, utility work wasn’t the only thing happening underground. By the time Prohibition hit Flagstaff, the tunnels had already begun taking on a very different life.
Bootleggers
As Prohibition tightened across Arizona, Flagstaff’s tunnels shifted from maintenance corridors to passageways for liquor running. Bootleggers used the underground routes to move alcohol between basements, back rooms, and hidden gathering spots without attracting police attention.
Local lore also ties parts of the system to small opium dens operated by Chinese railroad laborers and later by transit workers, though documentation is sparse and often based on oral history.
Reports from the Arizona Daily Sun and the Arizona Historical Society note that several downtown buildings connected to the tunnels, (particularly older hotels), were repeatedly flagged for illicit activity during the 1920s and 1930s, showing just how far the criminals underground ran.
READ MORE ON ARIZONA PROHIBITION: The 1914 Arizona Alcohol Ban That Predated National Prohibition
Tunnels Today
Most of Flagstaff’s tunnels have been sealed, rerouted, or absorbed into modern infrastructure, but remnants remain beneath parts of downtown. Some buildings have structural signs that the tunnels once connected to them, such as the Monte Vista Hotel and the Weatherford Hotel.
Today, local ghost‑tour groups and sites like Flagstaff Underground highlight these surviving spaces, pointing to reports of shadowy figures, cold spots, and unexplained noises tied to former speakeasies and rumored dens. While the city offers no official tunnel access, guided tours and private building visits still provide glimpses into the remaining corridors and the historic structures connected by Flagstaff’s subterranean past.
FUN FACT: Prescott supposedly has its own set of underground corridors with a similar legacy.
READ MORE ABOUT MONTE VISTA HOTEL: Arizona's Most Haunted Hotels and Their Chilling Ghost Stories
Though much of the underground network is completely inaccessible, its history still lies beneath the city’s historic streets. What began as practical infrastructure later became a route perfect for bootleggers and opium dens during prohibition. Today, Flagstaffs underground tunnels serve as a silent reminder of Arizona's wild past.
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