Polk is a borough in Venango County, Pennsylvania, United States. The population was 703 at the 2020 census. Polk State Center, a state-run facility for the intellectually disabled, was opened in 1897 and is located in the borough. In 2019, Pennsylvania announced a plan to close the facility. Families and residents sued Pennsylvania in an attempt to prevent th…Polk is a borough in Venango County, Pennsylvania, United States. The population was 703 at the 2020 census. Polk State Center, a state-run facility for the intellectually disabled, was opened in 1897 and is located in the borough. In 2019, Pennsylvania announced a plan to close the facility. Families and residents sued Pennsylvania in an attempt to prevent the closure.