I've reported on the historic Heron Park Sandhill Cranes in Vermilion County (IL) a couple of times in the recent past. Heron Park is just northwest of Danville, IL, about six miles west of the Indiana/Illinois state line.
I use the word "historic" here because the last known Sandhill nesting in east central Illinois was nearly 140 years ago, way back in 1872 (see: http://bit.ly/bvx8ty. The reference is on page 134 of the PDF, but the page number printed at the bottom of the page on the source document says page 120).
According to Illinois Natural History Survey biologist Steve Bailey: "This is quite a ways south of the most southern known Illinois nesting right now…at Grundy County's Goose Lake Prairie State Park." Heron Park is about 110 miles SSE of Goose Lake Prairie State Park!
The Sandhills managed to build a rudimentary nest and produce a single egg. See Brian Stearns' photos at: http://bit.ly/9FVe5F. When you scroll down to the "Sandhill Crane" entry you will see seven photos. The fourth through seventh Sandhill photos are dated May 14. You can see the egg in a couple of pictures.
Unfortunately the nest was built too close to the water. Earlier this week (the night of May 17/18) the water level rose from recent rains and flooded the nest, causing the cranes to abandon it. Last I heard, the cranes were still in the area though.
(UPDATE: THE PAIR OF SANDHILL CRANES WAS STILL PRESENT AT HERON PARK AS OF THE MORNING OF MAY 24).
(UPDATE: PHOTO FROM THE MORNING OF MAY 26, TAKEN BY BUD LEWSADER: http://bit.ly/aMl4cN).