The mounds and mound remnants in Beattie Park date from an era during the Late Woodland known as the Effigy mound Period.
This period spanned from about 700-1100 C.E. in the Upper Mississippi River Valley in parts of Iowa, Illinois, Wisconsin and Minnesota.
Native American Mound builders were not a single culture but several groups that interacted and made artifacts and structures such as mounds in similar ways.
The mounds in Beattie Park probably date from the early part of the time period 700-1100, when most of the effigy mounds seem to have been built.

The grouping represents the remnants of a cluster that originally included nine conical mounds, a linear mound, an earthen embankment, and two effigy mounds: a bird and a turtle.
Through the years, some of the mounds were destroyed or disturbed.
When Sears now the home of Rockford Art Museum constructed a parking lot on North Main Street in the mid-1950s one of the conical mounds was destroyed.
A bird effigy was destroyed when the North Main Manor apartment building was under construction across Park Avenue from the mounds.
The mounds and mound remnants in Beattie Park date from an era during the Late Woodland known as the Effigy mound Period. This period spanned from about 700-1100 C.E. in the Upper Mississippi River Valley in parts of Iowa, Illinois, Wisconsin and Minnesota. Native American Mound builders were not a single culture but several groups that interacted and made artifacts and structures such as mounds in similar ways. The mounds in Beattie Park probably date from the early part of the time period 700-1100, when most of the effigy mounds seem to have been built.
The grouping represents the remnants of a cluster that originally included nine conical mounds, a linear mound, an earthen embankment, and two effigy mounds: a bird and a turtle. Through the years, some of the mounds were destroyed or disturbed. When Sears now the home of Rockford Art Museum constructed a parking lot on North Main Street in the mid-1950s one of the conical mounds was destroyed. A bird effigy was destroyed when the North Main Manor apartment building was under construction across Park Avenue from the mounds.
Beattie Park Mound Group