Scotts Bluff National Monument was established due to the persistence of the public. On March 28, 1914, an inquiry was made to the Department of the Interior about the possibility of establishing a National Monument at Scotts Bluff. In 1916 and again in 1918, petitions were submitted to the federal government urging that a national monument commemorating the Oregon Trail be set aside. On December 12, 1919, Woodrow Wilson signed a Presidential Proclamation establishing Scotts Bluff National Monument.
Several parts of the park have been subject to archeological investigation. Forty-nine previously unrecorded archeological sites were located by pedestrian survey of Scotts Bluff National Monument in September 1991. Two sites are historic, while the others are prehistoric; some are stratified and many are buried by sterile overburden. Most of these sites were exposed as a consequence of arroyo and gully formation, which has initiated widespread erosion throughout the Monument. In the spring of 1992, two additional sites were discovered. Many fossils have been uncovered as well. The majority of fossils found at Scotts Bluff National Monument are located in the Monument’s badlands. Fossils of horses, oreodonts (extinct, sheep-sized, four-toed mammals), prairie dogs, foxes, turtles, rodents, beavers, and cats have been found in the badlands. Some of the richest fossil-bearing strata in Nebraska are found here. The Monument’s fossils have become type, or indicator, fossils for the Oligocene Epoch (40-25 million years before present) of the Cenozoic Era (65 million years to present).