A fire of unknown origin burned a portion of the deck at Meriwether's Restaurant and Lounge on Sunday morning.

The fire broke out on the northwest corner of the deck, and firefighters took about five minutes to extinguish it once they arrived, said Bismarck Fire Department battalion chief Don Peterson.

A portion of the recreation trail in front of Meriwether's, 1700 River Road, was closed, detouring bicyclists and others onto the road.

Owners Patrick and Jamie Irey opened the riverfront restaurant later Sunday, but seating on the deck was down from 125 to 140 people to only four tables.

"We call it our ambience seating," Jamie Irey said Sunday afternoon. "There's a lot to see."

She added that the restaurant planned to keep normal business hours.

Patrick Irey estimated the damage at "upwards of $25,000" for rebuilding the damaged portion of the deck.

The cause of the fire is under investigation, Peter-son said.