Exterior view of straw bale library in Mattawa, Washington taken in 2008
The town of Mattawa was originally platted in 1909 by E. and Eva Campbell, but was not incorporated at that time. With the construction of nearby Priest Rapids Dam and Wanapum Dam, the town boomed with construction workers. Mattawa was officially incorporated on June 3, 1958. The Port of Mattawa was also established in 1958. Mattawa is also home to the first straw bale library in the United States. On December 3, 2009, the City of Mattawa became a non-charter code city.
Mattawa is located at 46°44′10″N 119°54′7″W.
According to the United States Census Bureau, the town has a total area of 0.74 square miles (1.92 km2), all of it land.