This image is taken from the hilltop at Fort Abraham Lincoln State Park looking south southeast. In the center line is Sibley Island.
In the 1830s, Prinz Maximilian ascended the Missouri River with the artist Karl Bodmer. On coming up the Missouri River, they noted a burned out steamboat which had run aground on a sandbar. The steamboat as called "The Assiniboine," it was the second steamboat to travel upriver from St. Louis to Fort Union. It became grounded and overheated and burned. The sandbar grew to an island and is new part of the west bank of the Missouri River.
A different view of Sibley Island, looking west from the University of Mary, Bismarck, ND.
The island was renamed after General Sibley and his campaign against the Dakota in 1863. On July 29, 1863, Sibley engaged a force of perhaps as many as 2600 Dakota and Lakota warriors and fought them for three days in a battle larger and lasting longer than the Little Bighorn. Sibley was unable to take prisoners and could not estimate how many his men killed. The Sioux were encamped on the bluff overlooking the Missouri River and Apple Creek and held their ground until their women and children escaped. The "battle" was essentially a stalemant.