MOUNT COMFORT, Ind. -- Three Indiana state highway workers picking up trash Friday along I-70 found a little something extra inside an abandoned tire: more than $100,000 in cash.

Police spent hours unfolding, separating, counting and drying the thousands of wet bills at the Indiana State Police post at Pendleton. Investigators are checking the abandoned tire's tread marks to see if they can help determine a possible source of the cash.

The best early bet is that it may have been drug money.

The money was found inside a truck tire in a ditch on the north side of westbound I-70, just west of the exit for Mount Comfort Road in Hancock County, said Mike Burns, State Police spokesman.

The tire fell apart when the workers picked it up, revealing the massive stash of cash, police said. The workers, whose names were not released, called police about 1:30 p.m.

A drug-detecting dog that assists the State Police sniffed the money and found the scent of drugs on it, Burns said. No drugs were found.

Some of the money was rolled up and wrapped with rubber bands, Burns said. It's a method consistent with how police often find money transported by drug couriers, he said.

The bills were in $5 to $100 denominations, according to photos by the State Police.

The final tally of the cash likely won't be known until Monday, Burns said. The soggy condition of the cash delayed the counting, Detective Mitch Blocher said.

Detective Sgt. Keith O'Donnell said the tire appeared to be from a large truck and might have been at the location for some time.

"These three Indiana state highway workers are to be commended for their honesty and professionalism," O'Donnell said in a news release.

Ashley Hungate, spokeswoman for the Indiana Department of Transportation, said she did not want to talk about the three workers until the investigation is complete.

The I-70 interchange with Mount Comfort Road is about a mile south of Mount Comfort Airport.