Mo. Rev. Stat. § 226.490: Official highway maps — certain attractions to be designated, when.

The department of transportation shall designate, upon the face of the official highway map published by the department, the location of all municipalities which contain publicly funded Harry S Truman historical attractions. As additional tourist attractions are funded by state, federal or local sources, the governing body of each municipality containing such attraction shall inform the department so that new attractions can be included in the next scheduled printing of the official highway map.