The historic lime kilns south of Helena have been vandalized and repair costs are estimated to be around $4,000.
According to Helena-Lewis and Clark National Forest officials, heritage staff are currently working on a clean-up plan due to the recent graffiti.
Officials reported that the incident is in addition to the vandalism that occurred late last summer, which was scheduled to be cleaned up this year.
The incident is under investigation and if you have any helpful information, you are asked to contact Helena Forest Service law enforcement officers at (406) 449-5201.