FOIA documents reveal Monks Mound backhoe excavation exceeded permit depth. FOIA request from Illinois yielded 1,400+ pages about Cahokia Mounds, with 1,200 additional pages pending 2007 slump repair excavation used backhoes, digging 7 feet deep into Monks Mound's eastern, northwest, and western slopes, exceeding the 2-foot permit limit Permit was changed from 'no adverse effect' to claims there was 'no archaeological context' at the mound

FOIA docs reveal a 2007 repair at Cahokia's Monks Mound used backhoes digging 7 feet deep—exceeding the 2-foot permit. Officials shifted it from 'no adverse effect' to 'no archaeological context.' Researchers catalogued 85 colored soil samples from Indiana, the Carolinas, Louisiana, and British Columbia. The mound stands 100-105 ft tall with 13.85 acres of footprint. 📜⛏️

Key Facts

  • FOIA request from Illinois yielded 1,400+ pages about Cahokia Mounds, with 1,200 additional pages pending
  • 2007 slump repair excavation used backhoes, digging 7 feet deep into Monks Mound's eastern, northwest, and western slopes, exceeding the 2-foot permit limit
  • Permit was changed from 'no adverse effect' to claims there was 'no archaeological context' at the mound
  • Tires wired together and plastic sheeting were placed on the mound in the 1970s as erosion control, trapping water against the structure
  • A 10-foot-tall round-top mound previously existed on the western side before being pushed off to build a carriage road
  • A wooden Trappist monastery (Order of La Trappe) sat atop the mound and was burned in the 1700s or early 1800s
  • Over 85 Munsell color chips of distinctively colored soil were catalogued from different areas of Monks Mound
  • Colored soils originated from distant locations: Indiana (at minimum 200 km / 120 miles), North Carolina, South Carolina, Louisiana, British Columbia, and possibly New Mexico
  • Monks Mound is currently 100-105 feet tall (was 125 feet), contains 22 million cubic feet of earth, and has a 13.85-acre footprint, making it one of the world's largest pyramids

Source: The Roundtable Chronicles - Ep. 29 by Institute for Natural Philosophy