(PORT AUSTIN) -- The dispute over a 19th-century lighthouse lens located in the Thumb is headed for trial later this year. U.S. District Judge Thomas L. Ludington set the trial date for December 17 earlier this month. The settlement conference is scheduled for June 6 and a final pretrial conference will take place on December 3 if a settlement isn't reached. The federal government is suing Huron City Museums, saying it lacks approval to store and display the Fresnel lens that was used in the Pointe Aux Barques Lighthouse on Lake Huron. The U.S. Coast Guard gave it to the city of Harbor Beach in 1970's under certain conditions for display in the Grice House Museum. In 1987, Harbor Beach let Huron City Museums use it. The government says the lens is rarely available to the public and is stored in a building with no fire-suppression system, near Port Austin. Back in December, the foundation that runs the Huron City Museums asked a Bay City federal judge to dismiss the case.