The inscription "For the Benefit and Enjoyment of the People," over the park's north entranceway, symbolizes the ideals that created Yellowstone and defined the vision for all national parks to come. This arch, completed in 1903, was dedicated by and later named after President Theodore Roosevelt.

At Mammoth Hot Springs, hot waters heavily charged with lime have built up tier upon tier of elaborately carved and fretted terraces made of a hard rock called travertine. The springs that created the terraces are constantly moving and shifting--leaving old terraces dormant and forming new ones.

Bison almost became extinct from sport hunting and poaching, but a remarkable effort was made to preserve them at Yellowstone National Park during the early 1900s. The few bison that remained were rounded up into this corral for park officials to watch over and tourists to view. The greatly expanded bison herd was returned to the wild in the 1930s.

In 1915, automobiles were officially allowed to enter Yellowstone National Park. In 1920, 5000 cars flooded the park -- and their drivers had come to autocamp. This postcard shows one of the public autocamps that were built to accommodate the increased visitation to the park.

Approximately two square miles in area, Upper Geyser Basin contains the largest concentrations of geysers in the park--in fact, nearly one-quarter of all the geysers in the world. It includes Old Faithful along with several other well-known geysers. Colorful hot springs and steaming fumaroles also exist here.

Old Faithful is the most famous and celebrated geyser in the park--and indeed the world. Members of the 1870 Washburn Expedition, who camped near this geyser, named it Old Faithful because they discovered that it erupted at frequent and regular intervals (averaging about every ninety minutes).

Old Faithful Inn, a grand hotel built alongside Old Faithful geyser in 1903-4, was the first true rustic-style western resort. Architect Robert Reamer designed it to fit in with nature rather than--like other fancy resorts--to provide an escape from it. The interior continued the rustic look.

Fish Pot Hot Spring, also called "Fishing Cone," is a shoreline geyser that protrudes from the bottom of Yellowstone Lake. Early tourists claimed that they could catch a trout from the lake and cook it by dipping it into the spring's boiling water. This practice was prohibited in the 1930s.

During the first decade of the 1900s, tourists could take the park's Grand Tour by horse-drawn carriage. This tour involved stopping at a fancy hotel every night. The oldest surviving hotel in the park, Yellowstone Lake Hotel was built in 1891. Architect Robert Reamer added the colonial-style columns in 1903.

As the Yellowstone River flows north from Yellowstone Lake, it takes two great plunges into a deep canyon: first over the Upper Falls and a quarter mile downstream, over the Lower Falls. The Lower Falls, at 308 feet high, is the tallest falls in the park.