Tolleston Shoreline/Gibson Woods

I grew up in Hammond and now work in the Hessville section of Hammond. I find it interesting that part of the Tolleston Shoreline can be found near the Hess Cemetery at the intersection of 169th and Parrish. When the Tolleston Shoreline was first created, the upper Great Lakes had three outlets. There was the North Bay Outlet near Georgian Bay, the Port Huron Outlet past what is now Detroit, and the Chicago Outlet. The North Bay Outlet raised higher than the two other outlets and then couldn't carry water out of the lakes. Eventually erosion occured along the Port Huron Outlet, slowly lowering it and with it the level of Lakes Huron and Michigan so that the Chicago Outlet, having a floor of bedrock, became dry. Schoon, pg. 37.

During the Algoma phase about 3,800 years ago, the lake level dropped to its current level. The lower water levels were created from erosion at Port Huron and dry weather conditions. The higher water levels were caused by intervals of greater rainfall. This pattern created more than 150 small beach ridges. Some of these beach ridges can still be seen in Miller and the Tolleston/Brunswick areas of Gary. One of the longest dune ridges still remaining is in Hessville at Gibson Woods. Schoon, pgs. 37, 38. Gibson Woods "sits on 131 acres of virtually undisturbed land. The dune and swale features of the preserve were produced after the last glacier created ancient Lake Chicago, the forerunner of Lake Michigan. The parallel sand ridges still found in Gibson Woods today represent the effect of Lake Chicago as it retreated thousands of years ago." http://www.lakecountyparks.com/gibson.html

References: Schoon J. Kenneth, Calumet Beginnings

http://www.lakecountyparks.com/gibson.html