//
Photo: Yunner, CC BY-SA 3.0 via Wikimedia Commons
The first major entrance for Yellowstone was at the north boundary. Robert Reamer, a famous architect in Yellowstone, designed the immense stone arch for coaches to travel through on their way into the park. At the time of the arch's construction, President Theodore Roosevelt was visiting the park. He consequently placed the cornerstone for the arch, which then took his name. The top of the Roosevelt Arch is inscribed with "For the benefit and enjoyment of the people," which is from the Organic Act of 1916.
The Roosevelt Arch is a rusticated gate at the north entrance to Yellowstone National Park in Gardiner, Montana, United States. Constructed under the supervision of the US Army at Fort Yellowstone, its cornerstone was laid down by President Theodore Roosevelt in 1903. The top of the arch is inscribed with a quote from the Organic Act of 1872, the legislation which created Yellowstone, which reads: "For the Benefit and Enjoyment of the People".
© OpenStreetMap contributors
Often overlooked because it's not well-advertised to Park Visitors, the Archives hold records and materials that are part of the National Archives, but in this case the location is managed by NPS. The Archives are generally open to the public May through September, but advance appointments are required (mainly due to staffing constraints). In the Archives, you can find original photographs, journals and maps used by the original European expeditions to the area, along with more than a century of records, logs, photos and other materials starting from the Park's earliest days. Only a tiny fraction of these materials are represented in the various interpretive locations around the Park. The only danger to you here is time; it's easy to get lost in the history.
The North Entrance Road from Gardiner, Montana, to Mammoth Hot Springs, Wyoming, runs along the Gardner River. The road winds into the park, up the canyon, past crumbling walls of sandstone and ancient mudflows. The vegetation is much thicker in the canyon than on the open prairie down below, the common trees being Rocky Mountain juniper, cottonwood, and Douglas-fir. Low-growing willows also crowd the river's edge in the flatter, flood-prone sections of the canyon. Watch for wildlife in season: eagles, osprey, dippers, and kingfishers along the river and bighorn sheep in the steeper parts of the canyon.
A sign north of where the road crosses the Gardner River marks the 45th parallel of latitude. A little distance south of the sign, a parking area on the east side of the road is used by bathers in the "Boiling River", one of a very few spots in the park where visitors can soak in naturally-heated water. Bathers must walk upstream about a half mile (0.5 mi) from the parking area to the place where the footpath reaches the river. This spot is also marked by large clouds of steam, especially in cold weather. Here, the hot water runoff from the Mammoth Terraces, enters the Gardner River. The hot and the cold water mix in pools along the river's edge. Bathers are allowed in the river during daylight hours only. Bathing suits are required, and no alcoholic beverages are allowed. Boiling River is closed in the springtime due to hazardous high water and often does not reopen until mid-summer. It tends to be very crowded, so try to visit very early in the morning during peak season.
All of the red-roofed, many-chimneyed buildings in the Mammoth area are part of historic Fort Yellowstone. Beginning in 1886, after 14 years of poor civilian management of the park, the Cavalry was called upon to manage the park's resources and visitors. Because the Cavalry only expected to be here a short while, they built a temporary post near the base of the Terraces called Camp Sheridan. After five cold, harsh winters, they realized that their stay in the park was going to be longer than expected, so they built Fort Yellowstone, a permanent post. In 1891, the first building to be constructed was the guard house because it directly coincided with the Cavalry's mission - protection and management. By 1916, the National Park Service was established, and the Cavalry gave control of Yellowstone back to the civilians. Since that time, historic Fort Yellowstone has been Yellowstone's headquarters.
These mammoth rock formations are the main attraction of the Mammoth District and are accessible via boardwalk. These features are quite different from thermal areas elsewhere in the park as travertine formations grow much more rapidly than sinter formations due to the softer nature of limestone. As hot water rises through limestone, large quantities of rock are dissolved by the hot water, and a white chalky mineral is deposited on the surface. Formations here change rapidly, and while a favorite spring may appear to have "died," it is important to realize that the location of springs and the rate of flow changes daily, that "on-again-off-again" is the rule, and that the overall volume of water discharged by all of the springs fluctuates little.
Mt. Everts was named for explorer Truman Everts of the 1870 Washburn Expedition who became separated from his camping buddies, lost his glasses, lost his horse, and spent the next 37 days starving and freezing and hallucinating as he made his way through the un-tracked and inhospitable wilderness. Upon rescue, he was, according to his rescuers, within but a few hours of death. Everts never made it quite as far as Mt. Everts. He was found near the "Cut" on the Blacktail Plateau Drive and was mistaken for a black bear and nearly shot. His story, which he later published in Scribner's Monthly Magazine, remains one of Yellowstone's best known, lost-in-the-wilderness stories. It has also been published in book form, edited by Yellowstone's archivist Lee Whittlesey under the name Lost in the Yellowstone. Mt. Everts is made up of distinctly layered sandstones and shales--sedimentary rocks deposited when this area was covered by a shallow inland sea, 70 to 140 million years ago.