Following the devastation of the Sand Creek massacre on November 29, 1864, when an estimated 150 Cheyenne and Arapaho—including elders, women, and children—were killed by US forces, outrage swept through the tribes of Colorado and Kansas. Tensions exploded into open defiance. Many Cheyenne, including a large contingent of Dog Soldiers, gathered along the Republican River, while survivors of the massacre fled north seeking safety. Soon, a courier was sent to summon the Sioux and Arapaho, calling for a united stand against the settlers encroaching on their lands.
The tribes convened at Cherry Creek, near present-day St. Francis, Kansas, on January 1, 1865, to plan their retaliation. The council brought together the Northern Arapaho, the Cheyenne Dog Soldiers, and two Lakota subtribes: the Oglala, led by Pony Killer, and the Brulé, under Chief Spotted Tail. By early January, nearly 2,000 Cheyenne, Sioux, and Arapaho warriors had moved their camp along the South Platte River, which marked the northeastern border of Colorado.
At the center of this contested region stood the rough frontier town of Julesburg, a bustling hub that hosted the Overland Trail stagecoach station and Fort Rankin, later renamed Fort Sedgwick. On January 6, 1865, the first strike came. A small group of warriors ambushed a wagon train, killing twelve men. The attack was a prelude to something far larger.
In the pre-dawn hours of January 7, a massive offensive was launched against Fort Rankin. While most of the warriors concealed themselves in the nearby sand hills, Cheyenne Chief Big Crow and roughly ten of his men launched a daring assault on the fort before retreating, baiting the soldiers into pursuit. Captain Nicholas J. O’Brien, leading a cavalry of sixty men, rode out to chase them, unaware of the trap that had been laid.
The soldiers advanced toward a bluff about three miles from the fort, where nearly a thousand warriors lay in wait. When some of the younger warriors fired prematurely, O’Brien realized the danger. He ordered an immediate retreat, but the warriors surged forward, isolating a few soldiers who had not yet reached the safety of the fort. Those men dismounted and fought, but the overwhelming numbers proved too great.
In the ensuing clash, fourteen soldiers and four civilians were killed. Captain O’Brien and his remaining men barely made it back behind the fort’s defenses. With the garrison braced for another assault, the warriors instead wheeled their horses up the Platte River to the unguarded settlement of Julesburg. There, they plundered the stage station, the store, and the warehouse, seizing a substantial haul of supplies.
Within three days, they returned to their camp on Cherry Creek, Kansas, where the goods were eagerly distributed among the people. The camp soon echoed with the sounds of feasting and celebration as the tribes rejoiced in their hard-earned bounty. The attack did not go unanswered. General Robert B.
Mitchell assembled a force of 640 cavalrymen, a battery of howitzers, and about 200 supply wagons at Cottonwood Springs, near modern-day North Platte, Nebraska. Marching southwest, he intended to hunt down and punish the warriors who had struck Julesburg. By January 19, he arrived at their camp along Cherry Creek—only to find it abandoned days earlier. Battling frigid conditions and with more than half his men suffering from frostbite, Mitchell abandoned the chase and returned to base.
Meanwhile, the warriors continued their campaign across the South Platte River Valley, raiding ranches and stagecoach stops. The Arapaho struck targets in between. The Sioux hit areas east of Julesburg, while the Cheyenne targeted regions to the west. Traveling with them was George Bent, a man of mixed heritage, the son of Bent’s Fort founder William Bent and his Cheyenne wife.
Bent later described how, at night, the valley was illuminated by flames from burning ranches and stage stations. Eventually, every site was reduced to nothing, and darkness reclaimed the valley. On February 2, 1865, weeks after the initial attack, the warriors returned to Julesburg in full force. This time, they did not merely loot the town—they razed it to the ground.
They also plundered several wagon trains that had taken refuge there. The fifteen soldiers and fifty civilians barricaded inside nearby Fort Rankin dared not venture outside as smoke rose from the burning settlement. When Captain O’Brien and fourteen of his men returned to the fort and reached Julesburg, O’Brien fired a shot from his field howitzer, scattering the warriors, who quickly withdrew. As the fighting continued, a caravan of several thousand Sioux, Cheyenne, and Arapaho—including women and children—journeyed north toward the Black Hills and the Powder River country of present-day South Dakota and Wyoming.
Along the way, their warriors engaged in further skirmishes with the army at Mud Springs, near modern-day Dalton, Nebraska, and at Rush Creek, near Broadwater, Nebraska. The years of resistance stretched far beyond that winter. The conflict between the tribes and the settlers would persist for over a decade, culminating in the notorious Battle of the Little Bighorn in Montana in 1876.