In times of yore, to trace the path of a meal from your table to the source may have only been a short jaunt out to some nearby woods. But in these days of modern transit, when the foods that people consume hail from various regions of the United States and even the globe, that path, many times, is much more complex.

To help people understand how geographic information systems (GIS) can show information and to celebrate Geography Awareness Week, Linda Zellmer, the government and data services librarian at Western Illinois University Libraries, has utilized GIS to prepare a guide that shows where the foods consumed at the traditional Thanksgiving meal -- such as turkey, cranberries, squash and green beans -- originate.

"GIS is a collection of computer software and data used to organize and view geographically referenced information -- it helps people collect and organize information about places, so that it can be easily displayed," Zellmer explained. "I used the data from the 1997 and 2002 Agricultural Censuses for this project. The data for the Census of Agriculture is collected every five years."

Zellmer has compiled a website, available at faculty.wiu.edu/LR-Zellmer/thanksgiving.html, that links to PDF (portable document format) versions of the maps from 1997 and 2002. Some of the conventional Thanksgiving Day foods Zellmer compiled include green beans, carrots, cranberries, turkeys, pumpkins and sweet potatoes.

"Several years ago, when was I working at Indiana University (IU), I was looking for an idea to explain how GIS can be used to show information. Knowing that Thanksgiving was the following week, I decided to develop maps showing where the foods we eat on Thanksgiving Day are grown," she said.

In addition to the individual maps, Zellmer has modified a poster to display where Thanksgiving foods are produced in the U.S.

"I have continued to update the maps since I made the first set, and I decided to recreate the maps and modify the poster, which was developed by a friend of mine from IU, and use them here at WIU," Zellmer said. "I am looking forward to next year, because the data from the 2007 Census of Agriculture will be available in February, so I will be able to develop a new set of maps and poster."

Zellmer noted GIS provides government and other research agencies with a useful tool for planning and analyses.

"GIS is an expanded service University Libraries provides to people who use data and maps. I have started to collect data so that people have a wider variety of GIS data available," she said. "The geography department here also uses GIS, as does the Illinois Institute for Rural Affairs (IIRA), which is housed here at Western. For example, the IIRA has developed the Illinois Site Selection tool to help companies identify potential locations for businesses or industrial development," Zellmer added.

Educators in elementary, middle and high schools may also find Zellmer's work particularly beneficial for pre-Thanksgiving Day lessons.

"Teachers might be able to use the Thanksgiving maps to relate the food we eat to geography. They might also want to have the students examine the maps (and data) more closely to identify which states produce the most cranberries, turkeys and other foods. They might also want to dig a little deeper and look at weather, climate and growing conditions to try and determine why pecans only grow in southern states and cranberries only grow in a few states. It might be a good classroom activity when the students are eagerly looking forward to a long weekend," she said.

Visit http://faculty.wiu.edu/LR-Zellmer/thanksgiving.html to access Zellmer's maps and the comprehensive poster online.