Devils Tower National Monument, also known as Grizzly Bear Lodge, is the first national monument in the United States, established in 1906 in northeastern Wyoming, near the Belle Fourche River. It covers 5.4 square km (2.1 square miles) and features a natural rock tower, the remnant of a volcanic intrusion now exposed by erosion. The tower has a flat top that covers 1.5 acres (0.6 hectares) and fluted sides. It measures 867 feet high from its base and 1,267 feet as measured from the river valley; its summit has an elevation of 5,112 feet above sea level.
The tower probably formed when molten rock, pushing upwards, found a hard rock layer and was forced to spread out in a flat shape. Its color is mainly light gray and beige. Lichens cover parts of the tower, and sage, moss and grass grow on top of it. Squirrels and birds live at the top, and a pine forest covers part of the surrounding country; there is also a sizeable prairie dog village near the base of the tower. Wooden Leg, a Cheyenne from the north, recounted another legend told to him by an old man as they traveled together through the Devil's Tower between 1866 and 1868. Devils Tower was the first national monument in the United States, established on September 24, 1906 by President Theodore Roosevelt.
In addition to the Devils Tower in WY, only a few of the oldest attractions include Yellowstone National Park, the first national park in the United States, which was established in 1872. The children have the sisters take the bear to Devils Tower and trick him into thinking he has climbed the rock. As rain and snow continue to erode the sedimentary rocks surrounding the base of the Tower, more Devils Tower will be exposed. Some of these wooden stakes are still intact and are visible in the tower when walking the 1.3 mile (2.1 km) Tower Trail at the Devils Tower National Monument. O'Harra (from the South Dakota School of Mines) theorized that Devils Tower should be an eroded remnant of a laccolite. Geologists Carpenter and Russell studied Devils Tower in the late 19th century and concluded that it consisted of an igneous intrusion.
Scott Momaday (kiowa) was given the name Tsoai-talee (rock tree boy) after Pohd-lohk, an elderly Kiowa, linking the boy to the myth of the Devils Tower bear.