Infrared thermography has been an increasingly applicable diagnostic tool in the nondestructive testing of heritage objects. By measuring the surface temperature and emissivity, infrared thermography is measures heat radiation. Thermography has the ability to investigate objects without contact or causing any deleterious effects. This thesis aims to apply infrared thermography technology to evaluate earthen architectural finishes, and with the intent for subsurface identification of over-painted images. Evidence-based results from both passive and active thermography methods on test facsimiles will inform the efficacy of the technique on earthen finishes, and its applicability to in-situ testing on the north wall of Fire Temple at Mesa Verde National Park.