The damage was caused by the powerful waves whipped up by the storm that hit northwest Indiana with several days of lake-effect snow.
In some spots along the lakeshore the beach has been chopped off by the surf.
The dunes now look dramatically different. The 30-foot waves chopped off the dunes, destroying the gradual slope, and creating a sharp, cliff-like drop of up to 12 feet.
"After the storm, the waves washed all the beach and half of that marram grass foredune area out, where it was just a dramatic wall of sand going straight up and down, from 4 or 5 feet, all the way up to 12 feet steep. That's all along Porter County and parts of Lake County and probably...into LaPorte County, too," said Doug Stukey, Indiana Dunes State Park.
The Indiana Dunes State Park manager said it is the most intense storm since 1993. Some homes were threatened -- waves were eating away to the front of lakeside homes.
Park officials say, eventually, the dunes will be restored; Mother Nature will eventually solve the problem. They say they're already spotting some sand dunes in the water.