Fuel management, including thinning, is an important issue for communities and resource users striving to protect their values. Thinning reduces fuel loading in the overstory and can lower the likelihood of a sustained crown fire. However, surface fuel loading can increase in thinned stands as a result of harvesting, and could adversely affect fire behaviour and likelihood of sustained ignition. This project measured the probability of sustained ignition for thinned lodgepole pine stands where surface fuels, including logging slash, were left in place, and for stands where surface fuels were removed by piling and burning.