The installation of exhibits in the visitor center was essentially completed by November 1960.[243] Some of the materials used in the exhibits were donated by a number of individuals and institutions. Mr. Herbert Millard, son of the late Ben Millard, gave a large mass of sand calcite crystals now in the Small Wonders Exhibit. Dr. Winter of the University of South Dakota at Vermillion donated the plant collection in the Great Plains Grasslands Exhibit. The mounted badger in the Wildlife of the Grassland Exhibit was a gift from Orville Sandall of Kadoka, South Dakota. The skull of an Audubon Bighorn, on display above the Breaks in the Grassland Exhibit, was donated by Willard Sharp of Interior, South Dakota. In the exhibit showing a number of Indian artifacts are casts of early-man points donated by the University of Nebraska State Museum.[244] The South Dakota School of Mines and Technology in Rapid City, South Dakota, donated both the lower jaw and the upper jaw, including skull, of a fossilized titanothere, which is in the Badlands Bones Exhibit. The materials for the articulated oreodont fossil in the same exhibit were also donated by the school. The oreodont fossil is of particular interest because it was found northwest of Imlay, South Dakota about 100 feet from where a famous fossilized oreodont with unborn twins was excavated. The latter fossil is on display at the Museum of Geology at the school (see Figure 5).[245] The first full-time resident park naturalist for Badlands National Monument was assigned in June 1958 to aid with the local interpretive program.[246] For a number of years previously, a park naturalist who had been assigned to Black Hills areas of the NPS also served the national monument on an irregular basis.[247] [Illustration: Figure 27 CLIFF SHELF NATURE TRAIL The loop trail, completed in 1962, is constructed over a geological slump which has lush plant cover. To acquaint the visitor with the area’s natural history, a trail leaflet is provided. Here, naturalist-guided walks are offered daily during the summer months.[250]] On September 16, 1959, following the completion of the visitor center, the NPS dedicated Badlands National Monument. The featured speaker for the event was Fred A. Seaton, Secretary of the Interior, who gave the dedicatory address. Some 350 persons attended the ceremony.[248] Tragedy struck a short time prior to the dedication with the sudden death of Superintendent George H. Sholly on August 19. As a tribute to him, the new amphitheater was named the George H. Sholly Memorial Amphitheater.[249]