Ash Hollow State Historical Park

Just after sunrise on September 3, 1855, about six hundred soldiers under Brigadier General William S. Harney attacked the camp of Little Thunder's Sicangu Lakota band on Blue Water Creek, Mni Tho Wakpala, some six miles northwest of Ash Hollow. The army had been sent to punish the Lakota for the killing of Lieutenant John Grattan's detachment the year before. Eighty-six Lakota were killed, many of them women and children. About seventy survivors, mostly women and children, were marched to Fort Laramie and held until March 1856. For more than a century histories called it the Battle of Ash Hollow. History Nebraska says that name is wrong, and it is now more often called the Blue Water Massacre.

Lieutenant Gouverneur K. Warren, the expedition's mapmaker, gathered belongings from the camp and gave more than sixty to the Smithsonian in 1856. Little Thunder's descendants asked for them back in 2024, and on September 6, 2025, sixty-nine items were welcomed at the park's visitor center, which overlooks the valley, with a smudging ceremony led by Karen Little Thunder. They are kept there for Lakota people to see while the family decides their future.

The hollow itself was the trail's sweet spring. Wagons were let down Windlass Hill on ropes, where ruts still show, into a wooded canyon with water, wood and grass. Ash Hollow Cave holds charred remains from about 8000 B.C., and emigrants, Rachel Pattison among them, lie in the cemetery.