This Topical Fire Research Report is in response to a legislative inquiry concerning the number of wildfires that are started each year in Colorado from the escape of agricultural and prescribed fires. For the purpose of this report, the term 'escape' is used to describe an agricultural controlled burn or a prescribed fire that spread beyond the control lines and became a 'hostile' fire.

There are over 30 known underground coal fires in Colorado. Extinguishing or containing these fires has been challenging, primarily because delineating the subsurface extents of these fires is difficult. In this study, general characteristics of underground coal fires in Colorado are described. While the locations and the coal seams that are on fire differ, many common features are shared by the 30 plus known fires that are burning in the Colorado....