As people began to settle the area, support grew for the idea of preserving the Tower as a national or state park. In February 1892, Wyoming Senator Francis E. Warren (1844-1929) wrote the Commissioner of the General Land Office (GLO) seeking to protect Devils Tower and the Little Missouri Buttes (located several miles to the northeast). Using the Forest Reserve Act of the previous year, the GLO set aside 60 square miles as a temporary forest reserve. By June 1892 the reserve was reduced to 18.75 square miles (~12,000 acres), with the remainder being reopened to settlement.
Acting on the advice of the GLO, Senator Warren proposed that the reserve be set aside for a national park. At this point the reserve still included the Tower and the Little Missouri Buttes. On July 1, 1892, Senator Warren introduced a bill (S. 3364) in the United States Senate for the establishment of "Devils Tower National Park." The bill was read twice by its title and referred to the Committee on Territories. However, records indicate that Congress took no further action on the proposal. The area would remain protected as a forest reserve.