| 400,000,000 years ago |
Tropical Silurian Sea occupies Central United States with extensive coral reefs Age of
bedrock |
| 1,600,000 years ago |
Glaciers advance through most of
Illinois |
| 8,000-10,000 years ago |
Glaciers retreat from area Lake Chicago occupies area Beach ridges
form |
| 8,000 years ago to present |
Mother Earth activities
continue |
| 1974 |
Moraine Valley Board of
Trustees establishes Nature Study Area |
| 1975 |
Wildlife tree/shrub perimeter
planted |
| 1976 to present |
Prairie reconstructed and
rehabilitated |
| 1977 |
Pond established Archaeological studies/site
registered |
| 1978 |
Wetland habitat
established |
| April 22, 1990 |
Earth Day 20th anniversary
celebration |
| 1990 |
Nature Study Area
rededicated |
| 1991 |
Wetland restoration
completed |
| 1992 |
Sullivan Spring cleanup G. Jack Bradley Observation Deck
constructed |
| 1993 |
New pier built on pond |
| 1994 |
Wood duck nest boxes installed in
pond |
| 1995 |
Buckthorn eradication Trail
closures |
| 1996 |
Additional prairie planting Second pond
established |
| 2001 |
Nature Study Area rededicated West parking lot established Schulenberg inventory of
prairie |
| 2003 |
Observatory added to observation deck Selected prairie sites rehabilitated |
