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Coal Seam Fires

Please note: For your own safety, this area is closed. No trespassing beyond this point. All violators will be ticketed and fined up to $1,000 or 90 days in jail. For more information, please call 303-441-3440.

Underground Fires

Several feet underneath where you are standing, is a slow burning coal seam fire. Coal seam fire temperatures can reach over 1,000 degrees Fahrenheit. They have been burning in this area for over 100 years. On cold, wet days, when moisture flows down into the cracks, you can see steam rising nearby.


You are standing at the site where coal was first discovered in the Colorado Territory. Mining began in 1859 and this area has had a long, bloody and dangerous history. There were deadly strikes, deplorable working conditions and many other hazards. One of these hazards was fire.

Underground fires have been burning in this valley since the late 1860’s. Coal contains two percent sulfur, which can spontaneously combust when exposed to air and moisture. Coal mines in Marshall tend to be shallow; the proximity to oxygen further fuels these fires to this day. Because the fires can burn at 1,000 degrees or hotter, water vaporizes instantly on contact.

The only way to put the fires out would be to expose the coal seams and smother them with dirt, which would be difficult to do. Despite many efforts at extinguishing them, the coal seam fires still burn in the area today.

Spontaneous combustion is the most accepted explanation for the fires, but some speculate that striking miners may have set the fires to retaliate against the coal companies. Others believe illegal stills may have exploded and caused some of the fires. Such speculations highlight some of Marshall’s interesting past.


If you're interested in learning more about this area, Joanna Sampson's Walking Through History on Marshall Mesa brochure is a great resource. It might be easier to read the brochure on a computer screen.

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