WASHINGTON (AP) — Federal investigators say they've found credible evidence that male supervisors and staff in the maintenance division at Yellowstone National Park created a work environment that included unwelcome and inappropriate comments and actions toward women.

The Interior Department's inspector general says the division's supervisor should have known about and addressed some of the alleged misconduct.

The investigation began last September. The report released Wednesday says more than 100 current and former Yellowstone employees were interviewed.

The report says that between 2010 and 2016, six women who had previously worked in this unit had been subjected to derogatory comments or actions that made them feel uncomfortable.

Most employees interviewed — male and female — have told investigators they had not personally experienced or witnessed sexual harassment at the park.