This bill, titled the "Truth in National Parks Act," aims to ensure the historical and cultural accuracy of interpretive and educational materials at National Park Service (NPS) sites. It amends title 54, United States Code, to explicitly require that all NPS interpretive programs meet this standard of accuracy. A key provision prohibits the Secretary of the Interior from removing, obscuring, editing, or altering interpretive or educational materials if they are historically and culturally accurate and consistent with the unit's purpose. Exceptions are allowed only for updating existing accurate information or accommodating new accurate exhibits, with a mandatory consultation process involving relevant constituencies, including Indian Tribes. Furthermore, the bill mandates the replacement or restoration of any historically and culturally accurate materials that were removed or altered between January 20, 2025, and the bill's enactment date. Finally, the legislation requires the Comptroller General to submit a report within one year on the status of co-stewardship agreements between Indigenous communities and Federal agencies. This report is intended to provide recommendations for improving these processes to better fulfill Federal trust obligations to Indigenous communities.