Going through an old notebook, I discovered notes from a talk given ten years ago by Catherine Alington, at that time a PhD student in landscape ecology at Colorado State University-Fort Collins.
She researched fire cycles on both sides of the northern Sangre de Cristo range, and in some cases was able to go back three centuries. Her work was published in her dissertation, "Fire History and Landscape Pattern in the Sangre de Cristo Mountains" (1998).
According to my notes, some big fire years--when multiple valleys burned--were 1636, 1703, and 1851. Don't you wish you knew what was going on then?
Low-elevation forests burned on the average every 30 years, while higher elevations, above 10,000 feet, burned about every 100 years.
After teaching at the University of Illinois at Champagne-Urbana and at the University of Wellington, New Zealand (her home), she is now, according to Linked-In, the head of professional development for the New Zealand Police.