5 ILCS 555/1
The offer made by the Secretary of the United States Department of the Interior pursuant to Public Law 90-339, 82 Stat. 177, to retrocede such civil and criminal jurisdiction over private persons and property as the United States now possesses within the area of Jackson, Union and Williamson Counties known as Crab Orchard National Wildlife Refuge is accepted. However, this acceptance of the retrocession of jurisdiction shall not affect or impair the right, title and interest of the United States in and to the lands which may now or hereafter be included within the Crab Orchard National Wildlife Refuge, nor its power and authority by legislative or authorized executive action to make such rules and regulations as it shall deem needful or convenient for the promotion and protection of the Federal uses and purposes to which the areas comprising the refuge shall be devoted from time to time.
5 ILCS 555/1