( KTRS ) An ongoing effort to get an ancient historical Illinois site designated as a national park is getting a boost from U.S. Senator Dick Durbin.

The East St. Louis native has sent a letter asking President Obama to declare the Cahokia Mounds State Historic Site in Collinsville as a national monument. The property is currently designated, by the United Nations, as a World Heritage Site. It’s also a national historic landmark.

Cahokia is believed to have been inhabited from 700 to 1400 A.D. and was among the most complex societies of ancient North America.