Standing Rock Monument of Fort Yates, North Dakota: said to have once been a young woman, is sacred to the Sioux people.

The Standing Rock Sioux Reservation covers more than two million acres of grass plains, rolling hills, and buttes running alongside the Missouri River.
The reservation takes its name from a sacred rock formation that resembles a woman with a child on her back, that stands outside the Standing Rock Agency office in Fort Yates, North Dakota, and it is home to Lakota and Dakota Sioux people. The reservation was set up for the Standing Rock Sioux Tribe in 1889. Before that, it was part of what was known as the Great Sioux Nation, that comprised all of present-day South Dakota west of the Missouri River, including the sacred Black Hills and the life-giving Missouri River, that was broken up by the government to allow for white settlement.

The stone once stood in an Arikara village in the vicinity of the old town Winona, directly across the river from Fort Yates. As early as 1740, it had been documented that a Wakan (“holy” or “sacred” in the Lakota language) stone, described as a woman and a child turned to stone, had been carried from place to place for generations by the Dakota and Lakota People.
There are several stories explaining the origin of the stone.
According to the one inscribed on its plaque, it is the body of a young woman and her child. As story goes, she refused to accompany her tribe as they were forced to move south, and eventually turned into stone.Another version holds that the woman had been forced to marry and was unhappy about it. Upon returning to her family, she went to an isolated place near the village and slowly started turning to stone. Her small faithful dog climbed up into her lap and would not leave. Eventually both she and her dog turned completely to stone.

Either way, before his death in 1890, the Lakota leader Sitting Bull held a council where it was decided that the stone should no longer be moved and should remain at Fort Yates, North Dakota.
On November 6, 1886, the stone was fastened to a pedestal and spiritual leader Fire Cloud conducted a dedication ceremony near the banks of the Missouri River.