Rich in both military and early Native American history, Fort Abraham Lincoln was once an important infantry and cavalry post. It was from this fort that Lt. Col. George Armstrong Custer and the Seventh cavalry rode out on their ill-fated expedition against the Sioux at the Little Big Horn. Portions of the military post, including the Custer House, have been reconstructed. 

Popular with visitors is On-A-Slant Indian Village. Reconstructed earthlodges depict the lifestyle of the Mandan Indians, who occupied this site from about 1575-1781. 

A modern campground is located in a scenic wooded area adjacent to the Heart River with picnic sites and playground equipment. Walking along the gently sloping hills, visitors have a panoramic vista of the Missouri River from the park's nature and historic trails. 

The park also has 4 primitive campsites with horse corrals.