The shoes were stolen from a glass case at the museum in 2005 and bosses have been trying to track down the priceless memorabilia ever since.
Longrunning rumours suggest the sparkly slippers, one of four pairs used for the 1939 film, were placed in a sealed container and dropped into the Tioga Mine Pit, which has since filled with water.
Divers from the Itasca County Sheriff's Department began the new treasure hunt on Thursday (11Jun15) and returned again on Friday (12Jun15) after their initial search proved unsuccessful.
Their efforts, which are being filmed for an upcoming documentary, will continue throughout the weekend (12-14Jun15) as part of The Wizard of Oz Judy Garland Festival, held every year to mark the iconic actress' birthday.
Garland would have turned 93 on Wednesday (10Jun15).