The United States has 154 protected areas known as National Forests covering 188,336,179 acres (762,169 km²/294,275 sq. mi). The National Forests are managed by the U.S. Forest Service, an agency of the U.S. Department of Agriculture. The first National Forest was established as the Yellowstone Park Timber and Land Reserve on March 30, 1891, then in the Department of the Interior. In 1897, the Organic Act provided purposes for which forest reserves could be established, including to protect the forest, secure water supplies, and supply timber. With the Forest Reserve Act of 1891, the President of the United States was given the power to set aside forest reserves in the public domain. With the Transfer Act of 1905, forest reserves became part of the U.S. Department of Agriculture in the newly created U.S. Forest Service.