Battle of Big Mound The Battle of Big Mound was a United States Army victory in July 1863 over the Santee Sioux Indians allied with some Yankton , Yanktonai and Teton Sioux in Dakota Territory . Background . The defeat of Little Crow in the Dakota War of 1862 caused the widespread dispersion of the Santee Sioux or Eastern Dakota . Of the 6 , 300 Santee , 2 , 000 were taken prisoner . About 700 of the Lower Sioux from the Mdewakanton and Wahpekute bands remained at large . Most of the 4 , 000 Upper Sioux from the Sisseton and Wahpeton bands , who had been reluctant participants in the war , also remained free . A few of these refugees from the war fled to Canada , but more than 4 , 000 congregated in the summer of 1863 in a large encampment in present - day Kidder County , North Dakota . They were joined in the camp by an unknown , but probably sizeable , number of their Teton , Yankton , and Yanktonai relatives . Despite the defeat , however , Santee raids continued in 1863 , resulting in more than a dozen white deaths in Minnesota . To protect the frontier , Henry Hastings Sibley , appointed brigadier general of volunteers , was ordered by his superior , General John Pope , to lead a military expedition to punish the Santee . On June 16 Sibley departed from near Fort Ridgely and marched into the Dakota Territory . His army initially numbered 3 , 320 men , the largest military force ever assembled to combat Indians . Sibley ’ s ponderous column proceeded very slowly northwestward , hampered by drought , heat , and a lack of potable water . After a month of travel without having seen a single Indian , Sibley was informed by a group of buffalo hunters , mostly Métis Chippewa , of the location of a large Santee encampment of 600 lodges . With a stripped - down army of 2 , 056 men – 1 , 436 infantry , 520 cavalry , and 100 artillery plus 60 mixed blood and Sioux scouts – Sibley located the Santee encampment on July 24 . He halted nearby and sent scout and interpreter Joseph LaFramboise , one - half Sioux , to the Indian camp to propose a meeting with Upper Sioux leader Standing Buffalo . Sibley believed , probably correctly , that Standing Buffalo and his followers favored peace with the whites . However , Inkpaduta , believed to be implacably hostile to whites , and his band were also in the Indian camp . Battle . Anticipating a meeting between Sibley and Standing Buffalo , a group of Sioux and Sibley ’ s scouts gathered peacefully on a hill , called Big Mound , 300 to 400 yards from Sibley ’ s camp . An army surgeon , Dr . Josiah S . Weiser , approached Big Mound to greet several Indian friends , but was suddenly shot and killed by Tall Crown , a follower of Inkpaduta . The scouts and the Sioux opened fire on each other and the battle began . Sibley estimated that he faced 1 , 000 to 1 , 500 Indian warriors . They took cover behind hills and in ravines . Sibley sent forward two companies of Mounted Rangers to drive the Indians away from Big Mound and supported them with more soldiers and a six - pounder cannon . On reaching the top of Big Mound , Sibley could see the Indian warriors retreating , guarding the women and children of the Indian camp fleeing westward with their possessions . The Santee were poorly armed . Only about one half had firearms and those had little ammunition . Several hundred of the Mounted Rangers pursued the Indian warriors , protecting the flight of their women and children , until nightfall . Most of Sibley ’ s infantry devoted themselves to destroying the large quantities of jerky , buffalo robes , cooking utensils , and other goods left behind by the Sioux in their hasty flight . Sibley intended for the Rangers to continue the pursuit of the Sioux the next day , camping where they were for the night . However , by a mistaken order , the Rangers were ordered instead to return to their base , 12 miles from where they were . They arrived exhausted and Sibley was forced to rest his soldiers and horses the next day , July 25 , before continuing his pursuit on July 26 . Sibley ’ s casualties for the day were three dead and four wounded . In Sibley ' s official airport he estimated that 80 Indians had been killed and wounded , but his diary said that only 9 were killed . Results . The Sioux seemed to have little stomach to fight Sibley . Standing Buffalo may have surrendered his followers en masse if not for the killing of the army surgeon which precipitated this battle , The Battles of Dead Buffalo Lake and Stony Lake soon followed as Sibley pursued the Sioux westward .