Over the last century, the United States has evolved from a predominantly rural to an urbanized society with an exurban area currently referred to as the wildland urban interface (WUI). This WUI is critical as it occupies three to five times as much land area as urban areas with emerging and latent conflicts between traditional resource management and References of new residents. The effect of development on wildland fire management has received the most attentions. Increasingly, one of the most effective tools in the managers kit, fuel reduction by frequent understory burning, is off-limits because of safety and liability risks or public dislike of smoke. Fire risk in the WUI is greater than in wildland because there is a higher risk of catastrophic wildfire. The WUI, however, cannot be defined by simple proximity of forest to urban areas but more realistically is conceptualized as a set of complex social, physical, and biotic gradients. The Southern US exemplifies the problems of mixing urbanized land uses with fire-affected natural vegetation. Remote sensing and geographic information systems, along with spatial information at appropriate scale, will play a critical role in providing managers with monitoring capability that can also be used to educate the public about the wildland urban interface.