It was visited by the Lewis and Clark Expedition on their way up the Missouri River in 1804; nearby, they discovered a colony of prairie dogs, an animal previously unknown to scientists.

[6] The formation making up the hill is part of the Pierre Shale,[4] deposited in the deep marine waters of the Western Interior Seaway during the Campanian and Maastrichtian ages of the late Cretaceous period, 70–80 million years ago.

[4] For many years before the 1803 Louisiana Purchase, Thomas Jefferson had contemplated seeking a water route from the United States to the Pacific Ocean.

They were also directed to establish peaceable relations with the indigenous peoples of the region; to note mineral and other resources; to map the major physiographic features; and to describe and collect specimens of the flora and fauna of the territory.

[16] On April 7, 1805, the expedition's keelboat was dispatched back down the Missouri to St. Louis, carrying a collection of specimens including six living animals: a sharp-tailed grouse, four magpies, and the prairie dog.

On October 4, the prairie dog and the surviving magpie were inspected by President Jefferson in Washington, D.C.[4] They were then sent to Charles Willson Peale for his museum in Philadelphia.

Although the animals are generally regarded as pests by farmers and ranchers,[21] it was thought that the story of their discovery might draw visitors specifically to the area.

To fund Lewis and Clark-related projects, the city sold stuffed fabric prairie dogs made by local volunteers and dubbed "Lynch Dawgs".