MANISTIQUE, Mich. (AP) — A McBain man on Monday was sentenced to life in prison with no chance of parole for killing his wife by pushing her off a 140-foot cliff at Pictured Rocks National Lakeshore.

Judge William Carmody gave 46-year-old Thomas Richardson the mandatory sentence.

A Schoolcraft County jury found Richardson guilty of first-degree murder on April 16. He was charged in the June 2006 death of his 43-year-old wife, Juanita.

Richardson's lawyers argued that Juanita Richardson's death was an accident.

In court, Richardson read from a prepared statement asking his family to try to reconcile their relationships with his wife's family. Juanita Richardson's death has split the families apart.

Jeanette Ellens, Juanita Richardson's sister, said the family wanted to give Richardson to the state to have them take care of him.

Richardson plans to ask the judge to consider a motion to overturn the verdict. An appeal to the Michigan Court of Appeals also was being prepared.

The couple lived near the village of McBain in the northern Lower Peninsula, but were visiting the Upper Peninsula lakeshore when Juanita Richardson died.

She is the only person known to have suffered a fatal fall at Pictured Rocks since it opened in 1972.

Investigators said they were suspicious of Thomas Richardson from the beginning, as he gave conflicting accounts of what happened on the clifftop near the Miner's Castle overlook.

The delivery truck driver initially told police he didn't see his wife's fall but later said he did, first describing it as a suicide and later as an accident.

Friends and relatives who testified for the prosecution described the Richardsons' marriage as troubled and said Juanita had been planning a divorce.