Central America’s tropical forests have been felled more rapidly than those of any other world region during the latter half of the twentieth century. During this time, nearly half of Guatemala’s forests were eliminated. Most of this deforestation has been concentrated in the northern department of Petén. The remaining forests in Petén are now mainly concentrated in the Maya Biosphere Reserve (MBR), the heart of the largest lowland tropical forest in Central America. The pace, magnitude, and geography of this trend is of critical importance to forest conservation and rural development efforts. This article examines socioeconomic, political, demographic, and ecological factors behind settler land use and forest clearing among 241 farm households in the Sierra de Lacand ón National Park (SLNP), a core conservation zone of the MBR. Some of the factors positively related to forest clearing were household size, Q’eqchi Maya ethnicity, land owned in the previous residence, farm size, land title, and the cropping of velvet bean as a soil amendment. Education, off-farm employment, and farm distance to a road were negatively related to farm-level deforestation.