I hope this website is OK to show, since it references the Jackson Sun website.
This confirms that the phone call tip led to the search for the specific item:
http://www.upi.com/Top_News/US/2011...nt-for-missing-Tenn-woman/UPI-72981303702724/
Also says exactly where the item was found:
The Jackson Sun reported the undisclosed item was discovered along U.S. 641/Tennessee 69 in northern Decatur County.
So someone saw the "item" and phoned in a tip. If it was on the side of the highway then I am wondering if it was fairly large that the caller could see it as he/she was driving by. And, they pulled over and stayed with it until searchers could come check it out?