In a news release, the Dubuque Police Department said the vehicle was found near the Hawthorne Boat Ramp, by a marine services company dredging in the area.
The 1981 Mercury Zephyr was found to belong to Paul Knockel. Knockel, 53 at the time, was reported missing in Dubuque on Nov. 25, 1990. The case has been open since then.
Police say no human remains were found.
Anyone with information is encouraged to contact Corporal Clark Egdorf at (563) 589-4430. Anonymous tips can be submitted online, or by calling Dubuque Crime Stoppers at (800) 747-0117.
