Street trees grow along roadways within the public right-of-way. They are an important part of the urban forest due to their visibility to motorists and pedestrians, even if their numbers represent a small fraction of trees in urban areas. Little data are available that describe this resource at a large, statewide scale. In 2000, the Forest Service, U.S. Department of Agriculture, began a series of pilot studies to examine the structure and function of street trees throughout a State. Maryland and Massachusetts were the first two States included in the pilot (Cumming and others 2006). In 2002, the Forest Service initiated a pilot study in the State of Wisconsin to sample and monitor street trees in urban areas throughout the State.