620 ILCS 40/2
Every county has the power for airport, landing field or airport facilities purposes: (1) to acquire by dedication, gift, lease, contract, purchase, or condemnation under power of eminent domain within its boundaries or adjacent thereto, land in fee simple, rights in and over land, easements upon, over or across land, tangible and intangible personal property, and all property and rights necessary or proper; (2) to use any property now or hereafter owned by the county; (3) to appropriate money; (4) to levy and collect taxes; (5) to borrow money and issue bonds on the credit of the county; and (6) to be responsible for and have jurisdiction over all public roads and streets within the boundaries of any county airport, landing field or airport facility. The county has the same powers and duties with respect to such roads, as township highway commissioners, county boards, and city and village officers have over public roads and streets within their respective jurisdictions.
620 ILCS 40/2