Mecosta County Sheriffs investigate structure fire file photo and last updated 2021-03-31 21:08:35-04 According to the Mecosta County Sheriffâs Office the Fire Investigation Unit was requested to help identify the origin and cause of a structure fire at Blue Lake Tavern. The fire started around 5 p.m. Investigators were unable to determine the cause of the fire and did not discover anything suspicious. Blue Lake Tavern is closed until further notice and the investigation is ongoing, and this story will be updated as more details become available. Copyright 2021 Scripps Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.