The Washington Chapter of the American Society of Landscape Architects (WASLA) was established in 1973 to represent the landscape architecture profession in the state of Washington. At its inception the society had some membership overlap with its predecessor, the Washington Society of Landscape Architects (WSLA) and with other landscape architecture societies active in the state. WSLA formed in 1946 and was disbanded in 1970. In 1959 the American Society of Landscape Architects (ASLA) added a Pacific Northwest chapter, and in 1964 the Washington section was activated, largely to advocate for professional licensure. The state licensing law became effective August 11, 1969. In addition to the WSLA and both the Washington Section and the Pacific Northwest Chapter of ASLA, the American Institute of Landscape Architects (AILA) was represented in the state by the Cascade Chapter. In 1973, the Pacific Northwest Chapter of ASLA divided into sections for Washington, Oregon, and Montana-Idaho. WASLA increased its membership in the 1980s and became the dominant organization for landscape architects in the state of Washington.