Over thousands of years, waves have pushed sand from southern Wisconsin, grain by grain to the shores of Illinois Beach.  However, little sand now comes from Wisconsin due to beach protection measures and harbor jetties that divert sand into deep water.  Waves continue to move sand southward, but because there is little replenishment from Wisconsin, the remaining beach deposits in Illinois are eroding, endangering structures and wildlife habitat.  

Sand is periodically dredged from Waukegan Harbor and brought back to the North Unit to replenish and protect the beach. Without this intervention, Lake Michigan will continue to erode the shoreline, threatening the delicate ecosystems of the park.


At left, see the shoreline at the Illinois Beach State Park office recede from 2010 to 2015.

 Below, watch the shoreline change in South Unit and North Unit from 1994 to 2015.

Hover over image to pause.

For more information on erosion and erosion control, read "Coastal Erosion Along the Illinois Coastal Zone"