It has operated as a bar since 1887 in a building that was built as a bank in 1857.
The bar and restaurant was taken over by Steve Graham five years ago.
Workers reported the interior was trashed closing night. Police indicated that the owners damaged their own property and no laws were broken.
A Facebook post from the manager, who is the daughter if the owner, apologized for not handling the closure better.
On Friday an eviction notice was placed on the Owl Grill and Saloon's door from the Nevada County Sheriff's Office.
Although the closure was sudden, some businesses in old Grass Valley are confident that the business can be revived by another owner.