The ongoing search has raised speculation that maybe investigators have found new clues in the case. But officials have only said they are checking old leads and training on their search techniques.
Earlier in the week they used Springer Spaniels trained as cadaver dogs capable of detecting remains up to a decade old.
The 400-acre Hammel Woods was also searched shortly after Stacy Peterson turned up missing.
Stacy, the fourth wife of former Bolingbrook cop Drew Peterson, disappeared in October of 2007.
She hasn't been seen in more than five years. Peterson was recently convicted of killing his third wife, Kathleen Savio.