The decision follows a structural failure that damaged a portion of the Camp Preparation Plant on May 6.
Patriot expects to resume operations by June 30. Limited production may resume earlier if the preparation plant is repaired sufficiently to resume partial coal processing operations
Once full operations resume, 500 employees will return to work as annual production returns to 3.8 million tonnes.
The decision to idle the Highland mines came just weeks after the company announced it would be decreasing production at its Wells mining complex in West Virginia.
