Organization Act of the National Park Service, Ministry of the Interior Article 5

The Service may establish separate national parks/national nature park headquarters to address the official needs of each of its administrative regions.At least one sixth of the total number of employees employed at any such headquarters described in the preceding paragraph which is located in an Indigenous Area must have Indigenous status. In the event that the current number of Indigenous employees does not meet the stipulated ratio, additional Indigenous employees shall be hired as vacancies arise from the attrition of non-Indigenous employees.