An 80-year-old Bismarck man died after apparently being thrown from a horse-drawn wagon south of Mandan.

Morton County Sheriff Dave Shipman said Richard Biwer was found at 5 p.m. in a field south of Mandan.

Biwer had been driving the team of four horses in the field, which he owned, Shipman said.

"He apparently had been doing this for years," he said.

The wagon appeared to have gotten caught on a corner post on a fence, based on broken boards on the fence and wagon tracks around the fence, Shipman said. He said Biwer was thrown about 15 feet from the wagon. The medical examiner ruled his death accidental, caused by blunt force trauma to the neck from the fall, he said.

The horses pulled the wagon forward, and it was found caught in a tree.

"The horses eventually broke loose from the wagon," Shipman said.

A man driving by saw the horses, still in full tack, walking around and went to look for Biwer, Shipman said. He called 911 when he found him.

(Reach reporter Jenny Michael at 250-8225 or jenny.michael@bismarcktribune.com.)