Resource managers are frequently concerned that the area burned by wildfire over time will impede achievement of land management objectives. Methods that use the Poisson probability model to quantify that risk are described. The methods require a concise statement of an adverse wildfire outcome and information on fire frequencies and sizes. An example is presented that illustrates use of the risk assessment procedure to quantify the trade-off between burned acreage risk and the cost of a fuels treatment project that reduces risk.