Check out this July 1971 photograph of the Green Lake Bathhouse, which comes to us courtesy of our news partner seattlepi.com:
As modesty became less of concern, use of the bathhouse decreased. In 1970, the building was converted into a 130-seat theater which was operated by the city.
In 1981, the Parks Department ended its management of the theater program. However, the city maintained ownership of the bathhouse, which it leased to a private company. The Bathhouse Theater Company operated out of the building until it declared bankruptcy and closed in 1999.
Thanks for the tip, Shana!