An analysis of trees in Washington, D.C. reveals that this city has about 1,928,000 trees with canopies that cover 28.6 percent of the area. The most common tree species are American beech, red maple, and boxelder. The urban forest currently store about 526,000 tons of carbon valued at $9.7 million. In addition, these trees remove about 16,200 tons of carbon per year ($299,000 per year) and about 540 tons of air pollution per year ($2.5 million per year). The structural, or compensatory, value is estimated at $3.6 billion. Information on the structure and functions of the urban forest can be used to improve and augment support for urban forest management programs and to integrate urban forests within plans to improve environmental quality in the Washington, D.C. area.