Biomass and hydrocarbon fuel fires are two common sources of obscuring smoke which present significant operational challenges over a broad range of possible viewing wavelengths. This is especially true of very large fires where the primary smoke particles (approx. 0.1-0.3 um diameter) obscure vision by both scattering and absorption (single scattering albedo 0.3-0.9) and fire lofted debris and particle coagulation products reduces transmission in both the near and far IR. Large fires also cause obscuration by atmospheric dynamics. More than 50% of the biomass fires studies were capped with cumulus clouds, 3 or 4 of the largest fires produced precipitation, and one fire generated heavy showers of small hail and repeated lightning discharges. While these fires' smokes experienced efficient cloud and precipitation scavenging, the associated clouds and precipitation itself produced widespread obscuration.