The Theodore Roosevelt National Park Wild Horses Protection Act mandates the Secretary of the Interior to maintain a genetically diverse herd of at least 150 horses within the South Unit of Theodore Roosevelt National Park. This legislation amends existing law to ensure the permanent presence and protection of these animals. The bill requires the Secretary to develop a comprehensive management plan within 120 days of enactment. This plan must ensure cost-effective management of the herd while simultaneously safeguarding the park's natural resources from adverse impacts. Furthermore, the Act places strict limitations on the removal of horses from the park. Such removals are only permitted for maintaining genetic diversity, in emergency situations, or to protect public health and safety. Finally, the Secretary is tasked with annually monitoring and assessing the horse population, structure, and health. These findings must then be made publicly available, ensuring transparency in the management of the park's wild horse herd.