The elements of David Evans and Associates (DEA) can be classified as wind, land, and water. The engineering and architectural firm specializes in the sustainable design and the management of energy, land development, transportation, and water resource projects across the US (though most of DEA's work is in the Pacific Northwest). The firm also offers surveying services on land and in the water. DEA's projects include residential community development, heavy rail and highway design, energy facility design, and hydrographic surveys. DEA operates from 25 offices in Arizona, California, Colorado, Idaho, New York, Mississippi, Oregon, Texas, and Washington.