Randall Super, 57, of Cove (Polk County), was last heard from on Thursday when he called his wife from a Mount Vernon, Illinois motel.
According to the Missing Persons of America website, Super was on his way to visit his mother in Cleveland.
On Friday, Super checked out of the Thrifty Inn in Mount Vernon, and was seen on a surveillance camera going into and out of a Denny's restaurant and then getting into his truck around 7:30 that morning.
He has not been seen or heard from since. His wife has tried calling his cell phone but gets no answer.
Super is 6'2" tall, 190 pounds with short brown hair and glasses. He was driving his maroon 2000 Ford F-350 Super Cab maroon pickup truck with a maroon camper shell on the back. It has Arkansas license plate number 216 JPE.
The last time he stopped for gas was in Matthews, Missouri, about 125 miles south of Mount Vernon.
Officials say Super has type I diabetes.
If you see this man, call 911.