Amends the Downstate Forest Preserve District Act. Allows the board of a forest preserve district to establish a special forest preserve district retailers' occupation tax and service occupation tax after referendum of the voters. Allows the tax to used exclusively for general purposes, including education, outdoor recreation, maintenance, operations, public safety at the forest preserves, trails, acquiring and restoring land, and any other lawful purposes or programs determined by the board of that district. Includes referendum language and additional ballot informational language. Incorporates provisions from the Retailers' Occupation Tax Act to implement the tax. Amends the State Finance Act to create the Special Forest Preserve Retailers' and Service Occupation Tax Fund. Effective immediately.