Boulder High School’s tagline, “Still the First,” reflects its status as Colorado’s oldest established high school. Founded in 1875 as the State Preparatory School for the University of Colorado, Boulder High originally occupied a building on Pearl Street. The current building, 1604 Arapahoe Avenue, was built between 1936 and 1937 under President Franklin D. Roosevelt’s New Deal, as part of the Public Works Administration. But do people know that aside from Boulder High’s age, that it contains many underground, literally, secrets within its walls?
One such secret surfaced recently in a letter to The Owl from Mr. John Kettling, Boulder High Class of 1968. Kettling describes what he remembers as a drainage tunnel beginning somewhere in the school’s basement and extending under 17th Street toward the University of Colorado, possibly reaching Macky Auditorium or the University Theatre. According to him, students in the 1960s used this passage as a way to leave campus undetected during school hours. Whether exaggerated or not, his account raises the question: How much of Boulder High remains unseen?
To follow up, Kettling suggested Dr. Jason Potter, another Class of 1968 alumnus and now a philosophy professor at CU Boulder. Potter says he does not remember any tunnel during his time at BHS in the mid-1960s, but he does offer something relevant. Dr. Potter reports no direct memory of the tunnel from his time at BHS (1965–1967). However, he offers compelling nearby evidence. In the early 1990s, while living in CU Family and Graduate Student Housing at Marine Court on 20th Street, Potter saw a cockroach infestation traced to steam tunnels running under the housing along Boulder Creek’s north side, from 17th Street to Folsom Field. These warm, humid conduits carried steam and utilities; facilities cleared them with jewel wasps. Potter deems that the tunnels linking across 17th Street from BHS are a possibility, but not for certain…
Those steam tunnels are real and documented. CU Boulder maintains an underground network built mainly between the 1920s and 1960s that connects large parts of campus. Given how close Boulder High sits to this system, the idea that some kind of underground infrastructure exists nearby is not far-fetched. Whether it ever connected directly to the high school, however, remains unclear.
Online, the mystery continues to grow, although limited to forums like Facebook and Reddit. Posts on Reddit and local Facebook groups frequently bring up Boulder’s hidden tunnels, with some users claiming connections between BHS and CU. A 1970s video titled BHS Tunnels shows students walking through basement corridors lined with pipes, suggesting that at least part of the school’s underground space is accessible, though likely intended for maintenance rather than travel. Other accounts mention similar tunnel systems across Boulder, often tied to older infrastructure or New Deal-era construction.
Still, there is a gap between possibility and proof. Kettling’s memory places the tunnel running under 17th Street, while Potter’s experience involves utility tunnels serving campus housing. The overlap is suggestive, but not definitive. Kettling’s path hits 17th, not Arapahoe; Potter’s tunnels serve housing. Still, the reality that those steam tunnels and 1930s trenches exist leave room for speculation. Today, locked doors, safety concerns, and modern security make it nearly impossible to explore these areas firsthand. Still, for a more than-century-old building, who knows, the possibilities are endless….
