Native Americans formed trees to serve as trail markers. There are a number of them near Chicago.
http://www.greatlakestrailtreesociety.org/trail_tree_book.html
Trail trees - Wikipedia, the free encyclopedia
en.wikipedia.org/wiki/Trail_trees
Great Lakes Trail Marker Tree Society
www.greatlakestrailtreesociety.org/
Trail Tree Photo's page - Great Lakes Trail Marker Tree Society ...
www.greatlakestrailtreesociety.org/trail_tree_gallery.html
Images for trail marker trees
- Report images
Walk Past: 8 Amazing Native American Trail Marker Trees | WebEcoist
webecoist.momtastic.com/.../walk-past-8-amazing-native-american-trail-...
Mysteries of the Trail-Marker Trees - Illinois Steward - University of ...
web.extension.illinois.edu/illinoissteward/openarticle.cfm?ArticleID...
those old trees with very distinctive shapes that seem to point out destinations.
Trail Tree Project - Mountain Stewards
www.mountainstewards.org/project/internal_index.html
Amazon.com: Native American Trail Marker Trees: Marking Paths ...
www.amazon.com/Native-American-Trail-Marker-Trees/dp/0979789281
Dennis Downes, Elizabeth Fox] on Amazon.com. *FREE* super saver shipping on ...
Dennis Downes Studio | Trail Tree | Artist Dennis Downes Research ...
www.downesstudio.net/
Trail Marker Trees | Chicago Tonight | WTTW
chicagotonight.wttw.com/2011/11/01/trail-marker-trees
Trees Bent By American Indians Being Identified and Preserved ...
indiancountrytodaymedianetwork.com/.../trees-bent-by-american-indians...