While Fort Ridgely and New Ulm were going through their hours of agony, raiders continued to roam the prairies, going farther and farther afield to find new victims. At Lake Shetek, far out toward Dakota Territory, an isolated settlement was wiped out; of its fifty members, fifteen were killed, some were taken captive, the rest escaped. A Norwegian settlement on the upper Des Moines River was attacked and thirteen killed; the Sioux were raiding to the Iowa line. Far to the northwest, across the Red River in present-day North Dakota, war parties attacked Fort Abercrombie. It was a post no more designed for defense than Fort Ridgely, but its small garrison built breastworks of cordwood, fought off two attacks, and then waited uneasily for six weeks before help arrived.

Panic had spread across Minnesota, and thousands fled eastward in a frantic exodus. Many saw their families butchered and made hazardous escapes, hiding in sloughs and thickets, living on berries or a few carrots grubbed at night from a vegetable garden beside the ashes of a farm home, often bearing frightful injuries, and proving what toughness lies in the human body faced with a fight to survive.

Twenty-three counties were completely depopulated, a region 50 by 250 miles. An estimated 30,000 people fled their homes and some of them kept going right out of the state, never to return. How many died is a matter of guesswork. Too many went uncounted, buried in hasty graves soon overgrown by the sod, or fallen in lonely places where prairie fires and the natural forces of dissolution wiped out all traces of them. Sober citizens estimated the dead as high as two thousand; eight hundred is accepted as a conservative figure.

After the defeats at Fort Ridgely and New Ulm, the Sioux moved their villages up the Minnesota River, five miles northwest of Upper Agency. The whites would be striking back soon; it would be just as well to have wives and children in a safe place.

And a white force was on the way. As soon as hard-riding Private Sturgis brought news of catastrophe at Lower Agency and the ferry, Governor Alexander Ramsey rode to Fort Snelling to see what troops were available, then called on his personal friend and political foe, Henry Sibley. He commissioned Sibley a colonel, put him in charge of operations against the Indians, and told him to get moving.

Henry Sibley had been a fur trader for years, knew the habits and character of the Sioux, and was acquainted with many of their leaders. He had also been the first governor of the young state. All in all, a perfect choice—except that there is argument about whether he knew anything about fighting Indians. It all depends on which historian you read.

Sibley took his command, four companies of infantry, upriver to St. Peter, sixty-five miles from Fort Snelling. During the three-day trip, reports became more and more alarming. The lower Minnesota River valley was in a state of mixed panic and high excitement, with every arriving refugee bringing new alarms. Sibley listened, grew worried, hesitated, and then sent back to the Governor for more men, better guns, more supplies. Ramsey complied, while additional hundreds of local volunteers streamed into Sibley’s camp. On the morning of August 26, he finally set out with a force of 1,400, at a speed so ponderous that his army covered all of six miles that day and camped virtually within sight of the evening cooking fires of St. Peter. The mounted forces, however, pushed on all night and reached Fort Ridgely early the next morning. The main force arrived a day and a half later.

Sibley sent women and children back east under escort, and after three days, sent a detachment toward Lower Agency to bury dead and to look for signs of the enemy. The burial party, under the command of Major Joseph R. Brown, traveled slowly because it found a great deal of melancholy work to do along the road. During its second day, the detachment found one living survivor, Mrs. Justina Kreiger, who had been a member of the Sacred Heart Creek settlement attacked on the first day of the uprising. This tortured woman had been shot and slashed with a knife; she had seen husband, friends, and one of her children butchered; and she had been without food (except for a few berries) for twelve days. She was emaciated, half-naked, covered with dirt and caked blood, and too dazed and weak to tell her story. But alive she was, and one wagon was emptied and lined with grass and blankets, and she was placed in it.

Major Brown saw no Indians, but they saw him. A large war party, headed downriver to plunder, sighted the detachment and followed it until it made camp near the head of Birch Coulee, a gully or ravine about three miles from the river. It was a bad campsite. The wooded coulee, offering fine cover for ambush, was little more than a rifle shot away, and to the north a swell in the prairie would protect any enemy approaching from that direction.