A portion of the southwestern corner of Yellowstone National Park will be temporarily closed starting September 4. The closure is needed so park staff can repair, restore and recover a section of previously pristine backcountry where an illegal trail has caused resource damage.  A remote section of the Bechler area along the southwest boundary of the park will be closed while repairs are underway. This closure will not affect any visitors using the park’s authorized trail system. Signs and maps will be posted at access points along that section of the park boundary.