Biological invasions, the arrival, establishment and spread of nonindigenous organisms that have detrimental effects on native species, have become an increasing problem affecting the health of forests worldwide. In July 2002, beetles collected from ash trees in southeastern Michigan and Windsor, Ontario were identified as Agrilus planipennis Fairmaire (Emerald Ash Borer (EAB)). Since the initial discovery of this exotic invasive wood-boring beetle, it has spread and established in 13 counties in Michigan and isolated outbreaks have occurred in Ohio, Maryland, Indiana and Virginia. EAB has been found infesting the three major ash species in Michigan green ash (Fraxinus pennsylvanica), white ash (Fraxinus americana), and black ash (Fraxinus nigra ) as well as horticultural varieties. With the current known geographic range of EAB, the opportunity exists to establish baseline data on the health of the ash resource in Michigan before the perhaps inevitable spread of the pest. During the summer of 2004, a network of permanent monitoring plots will be established throughout the state. This ash monitoring plot system will allow documentation of the present state of the ash resource, changes in the ash resource over time, and determination of the abiotic and biotic factors that are affecting the health of these trees. In addition, we aim to determine the distribution and spread of EAB in Michigan and factors associated with its presence or absence. A website containing a project description, maps, and educational materials has been developed at www.michiganash.org.