Peregrine falcons have been spotted in Effigy Mounds National Monument/NPS

While a program to restore peregrine falcons to their habitat in Effigy Mounds National Monument in Iowa back in the late 1990s failed, a pair of the birds recently were spotted nesting on a bluff along the Mississippi River inside the park boundaries, according to park staff.

On Friday, park staff will offer a special evening program to discuss the falcons' history in the landscape, and their recent return there. The program will be held at 7 p.m. in the mounment's visitor center in Harpers Ferry, Iowa.

Back on May 18, William Smith, a biologist volunteer with the Raptor Resource Project, spotted peregrine falcons in what appeared to be a nest on the bluffs over the Mississippi River. 

Effigy Mounds was the site of recovery and reintroduction efforts focused on restoring peregrines to their native habitat. Starting in 1998 and continuing into 1999, nine birds per year for a total of 18 were released into the wild from hacking boxes attached to the cliffs of Effigy Mounds. The birds immediately dispersed both up and down river. In 2000, the first documented nest was confirmed in Queens Bluff, Minnesota, however, no nests were ever discovered in Effigy Mounds until now.

Peregrine falcons lived for countless generations along the cliffs of the Upper Mississippi River. The bluffs echoed with their shrill cries and the sky was filled with their spectacular aerobatic courtship displays. The peregrine disappeared from the cliffs along the Mississippi River in the 1960s due to the use of DDT. The last recorded pair to nest in the area disappeared in 1964.