Black Hills Expedition ( 1874 ) The Black Hills Expedition was a United States Army expedition in 1874 led by Lieutenant Colonel George Armstrong Custer that set out on July 2 , 1874 from modern day Bismarck , North Dakota , which was then Fort Abraham Lincoln in the Dakota Territory , with orders to travel to the previously uncharted Black Hills of South Dakota . Its mission was to look for suitable locations for a fort , find a route to the southwest , and to investigate the possibility of gold mining . Custer and his unit , the 7th Cavalry , arrived in the Black Hills on July 22 , 1874 , with orders to return by August 30 . The expedition set up a camp at the site of the future town of Custer ; while Custer and the military units searched for a suitable location for a fort , civilians searched for gold , and it is disputed whether or not any substantial amount was found . Nonetheless , this prompted a mass gold rush which in turn antagonised the Sioux Indians who had been promised protection of their sacred land through Treaties made by the US government , and who were later to kill Custer at the Battle of the Little Big Horn in the Great Sioux War of 1876 - 77 between themselves and the United States . The entire expedition was photographed by William H . Illingworth , an English photographer who accompanied Custer after selection by the then - Captain William Ludlow . Ludlow , the engineer for the expedition , financed Illingworth ' s photography and paid him $ 30 per month to provide photographic plates for the US Army , of which he made 70 in all . Expedition . Embarking for the Black Hills . Custer embarked on his expedition with 1000 - 1200 men , in 110 wagons with numerous horses and cattle of the 7th Cavalry , along with artillery and two months food supply . The expedition also took a number of Native American scouts led by Bloody Knife and Lean Bear . At the time , the Black Hills were relatively unknown , with few white expeditions ever returning from them The commander of Custer ' s engineering corps , Captain Hardy , assured him that he had heard of them and had them marked on his maps , but had never entered them during his earlier expeditions . En route to the Black Hills , Custer ' s party managed to locate the track of Hardy ' s group when they spotted two lines of sunflowers that had grown along the ruts of his passing wagons . Custer and his force entered the Black Hills from the north , travelling south at a slow pace of no more than four or five miles a day on some occasions . On July 31 , 1874 , the wagon train reached Harney Peak , and Custer together with Ludlow took three or four men to climb it . In the mean time , the rest of the expedition made camp at the mountain ' s base at the newly named Custer Park . While the majority of the force remained there , Custer took a small unit with him to locate a suitable site for a new fort . By August 2 , 1874 this force had reached a point eight and a half miles south - east of the mountain , to a location they named Agnes Park , having had a number of peaceful encounters with native American settlements . On August 7 Custer shot and killed a grizzly bear , forever claiming this to be his greatest achievement as a hunter . Discovery of gold . Throughout the expedition , civilian experts who accompanied the expedition located traces of gold in the rivers . The first discovery goes uncredited , however an undated diary entry by William McKay , a miner accompanying the expedition , notes that while camping at the newly named Custer Park , " In the evening I took a pan , pick and shovel , and went out prospecting . The first panful was taken from the gravel and sand obtained in the bed of the creek ; and on washing was found to contain from one and a half to two cents , which was the first gold found in the Black Hills . " A significant discovery was made on August 1 when tests of the soil by the French Creek determined that a miner could earn as much as $ 150 per day mining in the Black Hills . Custer wrote in a letter of August 15 , 1874 to the Assistant Adjutant General of the Department of Dakota that " there is no doubt as to the existence of various metals throughout the hills . " His messages were carried by scout Charley Reynolds to Fort Laramie , and from there it was telegraphed to the press eastwards . The force remained there at Agnes Park until August 15 whereupon it turned around to return to Fort Lincoln . The expedition returned on August 30 , with the scouts returned to their reservations on September 10 . In total , Custer and his forces had traveled for 60 days over 883 miles . Organization of the 7th Cavalry . The table of organisation for the 7th Cavalry for the Black Hills Expedition of 1874 was as follows . References . Printed sources : Websites :