Compound Mound - Conical mounds connected to linear mounds. Most consist of 3 conical mounds and 2 linear mounds, but there is one at Effigy Mounds National Monument that has seven conicals and is 300 feet long.
Did You Know?
In the South Unit of Effigy Mounds National Monument, the Marching Bear Group of 10 bear mounds, three bird mounds and two linear mounds represent the best preserved group of effigy mounds present today from the Effigy Mound Culture.