BEMIDJI -- A rogue lumberjack or lumberjacks have done some unauthorized landscaping at the city's disc golf course- at the price of six decades-old trees.

A post Friday on the city of Bemidji Parks Department's Facebook page said five oak trees and one mountain ash tree were cut down earlier this week near the disc golf course trail at City Park.

"It appears they cut the trees to change the course - make a new lane for the fairway," the post said. "The City has, in the past... taken action for property destruction against those who have trimmed, limbed or removed trees from park/public property."

The post described the oaks that were cut down as a "slowly growing tree, and an extremely valuable natural resource."

"It's difficult to estimate a replacement value for the trees as replacing them due to the size and age is impossible," the post said.

However, the cost of putting in a new, 2"-diameter sapling would be about $350 per plant, the post said.