Wildland fire is a significant component of nearly all North American ecosystems. High intensity, stand-replacement fires are normal in certain ecosystems, especially in the northern Rocky Mountains. Wilderness fire managers are obligated to let fire operate as a natural influence to the extent that this is possible. Where wilderness areas incorporate stand-replacement-type fire ecosystems, ecologically significant prescribed natural fires must reach stand-replacement fire intensities. However, because weather forecasting capabilities are limited, fire managers are unable to predict whether prescribed natural fires will escape prescribed boundaries. Moreover, the effectiveness of suppression actions decreases as wilderness fires increase in size. Thus, fire managers face the dilemma of managing for natural fire influences on ecosystems, with the consequence of increasing the potential for escaped fire situations.