Section 20 ILCS 3420/6 - Review of private undertakings(a) The Department shall adopt standards, including maps, in accordance with the Illinois Administrative Procedure Act, for determining whether a private undertaking will affect a high probability area for the statewide occurrence of archaeological resources. The Illinois State Museum shall propose to the Department maps of high probability areas for each county in the State that the Department shall consider in creating its standards. The maps shall be made available to any interested person and shall be filed with all regional planning commissions to assist in the planning process.(b) High probability area maps for each county in the State shall be prepared by the Illinois State Museum and submitted to the Department. Until maps for a particular county are adopted by the Department as rule, the Director's review within that county for archaeological resources shall be limited to determining whether there are known archaeological sites within the area of the undertaking. If there are no known sites, the Director shall so notify the State agency or the local or private designee responsible for the private undertaking and the undertaking may proceed. If there is a known archaeological site within the undertaking, the Director shall so notify the state agency or the local or private designee responsible for the private undertaking and may require additional archaeological investigations.(c) The Director shall not require archaeological investigations for private undertakings outside high probability areas unless the undertaking may affect a known archaeological site. An archaeological investigation may be required only on that portion of property within a high probability area or where a known site exists on that property. Archaeological investigations shall be required in high probability areas unless the Director indicates that such investigations are not necessary.