High Quality Content by WIKIPEDIA articles! The Elwha Dam is a 108-ft (33 m) high dam located in the United States, in the state of Washington, on the Elwha River approximately 4.9 miles (7.9 km) upstream from the mouth of the river on the Strait of Juan de Fuca. The dam was built under the direction of Thomas Aldwell. Aldwell previously bought up tracts of land around the river, and with the help of Canadian financier George Glines, began construction of the Elwha Dam in 1910.