The Battle of Platte Bridge, also called the Battle of Platte Bridge Station, on July 26, 1865, was the culmination of a summer offensive by the Lakota Sioux and Cheyenne Indians against the United States army. In May and June the Indians raided army outposts and stagecoach stations over a wide swath of Wyoming and Montana. In July, they assembled a large army, estimated by Cheyenne warrior George Bent to number 3,000 warriors, and descended upon Platte Bridge. The bridge, across the North Platte River near present-day Casper, Wyoming, was guarded by 120 soldiers. In an engagement near the bridge, and another against a wagon train guarded by 28 soldiers a few miles away, the Indians killed 29 soldiers while also suffering at least eight dead.
Background
The Sand Creek Massacre in Colorado in November 1864 catalyzed an uprising among the Plains Indians of the central Great Plains. About 4,000 Brulé Lakota, Southern Cheyenne, and Southern Arapaho, including about 1,000 warriors, moved north from Colorado and Kansas to join their northern relatives in the Powder River Country of the future states of Wyoming and Montana. Along the way they raided ranches and wagon trains, acquired a huge amount of plunder, and fought battles with the army at Julesburg, Mud Springs, and Rush Creek.
With the coming of spring 1865, their horses recovering strength after the long winter, the Lakota and Cheyenne decided to attack along the North Platte River during the summer. Messages were sent to Sitting Bull and the Hunkpapa Lakotas in North Dakota and Montana and the Hunkpapa agreed to attack Fort Rice in North Dakota simultaneously. In the opinion of historian Stephen E. Ambrose, the plan was the closest the Lakota and Cheyenne ever came to a "concerted, unified offensive movement."Ambrose, Stephen E. Crazy Horse and Custer New York: Anchor Books, 1996, p. 159
As a military force, the Indians had serious weaknesses. "It was only in midsummer and early winter that they could raise a large force, and even then they could not hold their warriors together for a longer period than a week or ten days."Hyde, George E. Red Cloud's Folks Norman: University of Oklahoma Press, 1937, p. 118 The Indians had few guns and little ammunition, and their basic weapon, the bow and arrow, was nearly worthless against a well-fortified or entrenched enemy. The Indians had no command structure; individual Indian warriors followed only who they wished and fought only when they wished and they took the offensive primarily to acquire horses and to win personal, rather than collective, honors. Their fatal flaw was that they "were unable to turn a battle into a campaign."Ambrose, p.66 Moreover, the Indians were divided among themselves. Only a few Arapaho participated in the war, and about 1,500 Lakota, mostly Brulé under Spotted Tail, had taken up peaceful residence at Fort Laramie in Spring 1865. The Lakota living near the fort were known as the "Laramie loafers."Ambrose, pp. 154-155; McDermott, p. 69
The U.S. Army also had weaknesses. The soldiers arrayed against the Lakota and Cheyenne were primarily Civil War draftees or "galvanized Yankees"—Confederate soldiers captured by the Union who agreed to fight Indians on the frontier in exchange for their freedom. With the Civil War winding down in spring 1865, the soldiers wanted out of the army and were unenthusiastic about fighting Indians. Many soldiers deserted or threatened mutiny.Ambrose, p. 163
Preliminary encounters
Deer Creek Station. Mixed-blood Cheyenne/white George Bent joined a war party of 100 Cheyenne, divided about equally between the northern and southern branches of the tribe. Heading southward from their camp on the Powder River the Cheyennes reached the North Platte 28 miles east of the Platte River Bridge, near present-day Glenrock, Wyoming, on May 20. Two companies of U.S. cavalry, comprising about 100 men, were stationed at Deer Creek Station.
About 25 of the Cheyenne encountered and fought four soldiers about three miles upriver from the station. The Cheyenne were repulsed. Another band attacked a group of seven soldiers, killed one, and captured 26 horses. The soldiers claimed to have killed five Indians in these skirmishes."Wyoming Indian Encounters" http://www.3rd1000.com/history3/events/wyoming_indian_encounters.htm, accessed 8 Nov 2012 As is often the case, the Indian story is substantially different. Bent says the Cheyenne forded the flooded North Platte River and surprised the soldiers at Deer Creek Station, who refused to come out of their stockade. After exchanging fire with the soldiers and suffering no casualties, the Indians abandoned the attack and re-crossed the North Platte with their stolen horses. According to the official report of the army, a 25-man contingent of soldiers tracked the Indians to the river, but could not cross due to high water. Bent, to the contrary, said the soldiers stayed in their stockade and did not pursue the Indians."Wyoming Indian Encounters" http://www.3rd1000.com/history3/events/wyoming_indian_encounters.htm, accessed 8 Nov 2012; Hyde, George E. Life of George Bent Norman: University of Oklahoma Press, 1968, p. 204 Before returning north to their villages, the Cheyenne reconnoitered the Platte River Bridge, exchanged a few shots with the soldiers guarding the bridge, and attacked a wagon train guarded by soldiers, capturing 250 mules.Hyde, Bent, p. 205-206
Raids by Lakota took place on May 26 at Sweetwater Station and St. Mary's Station, west of Platte Bridge, prompting the army to close the Oregon Trail to civilian traffic on May 30.Robrock, David P. "The Eleventh Ohio Volunteer Cavalry on the Central Plains, 1862-1866" Arizona and the West Vol. 23, No. 1 (Spring 1983), p. 41
Dry Creek. With the Oregon Trail closed to traffic, the Indians shifted their attention southward to the Overland Trail. On June 2, Fort Halleck, near present-day Elk Mountain, Wyoming learned of Indian attacks on stage stations to the west. He sent 32 soldiers to investigate and found three stage stations abandoned and all their employees holed up at Sulfur Springs Station, eighty miles west of Fort Halleck. The soldiers returned the civilian employees to their stations and left a detachment to guard each station. The Indians re-raided the stations and stole most of their livestock, leaving the soldiers on foot.Robrock, p. 41
Meanwhile, the Indians tried to lure soldiers at Platte Bridge Station into an ambush. On June 3, they fired on the Station and Lt.Col. Preston B. Plumb, 11th Kansas Cavalry, and 22 soldiers sallied in pursuit of them. Near Dry Creek, the soldiers were ambushed by 60 Indians, but rescued by twenty additional cavalry went out to help them. Two soldiers were killed and they claimed to have killed one Indian. The builder of the bridge, an elderly civilian named Louis Guinard, disappeared. A boot containing part of his leg was found months later.Robrock, pp. 42-43; McDermott, p. 68
Sage Creek Station. On June 8, an estimated 100 Indians attacked the Sage Creek Station, west of Fort Halleck near present-day Saratoga, Wyoming. The five soldiers and 2 civilians in the station ran out of ammunition and attempted to flee eight miles west to Pine Grove Station with the Indians in pursuit. Five of them were killed. The Indians continued to raid in the area, killing two civilians but focusing on relieving the stagecoach stations of their livestock.McDermott, John D. Circle of Fire: The Indian War of 1865 Mechanicsburg, PA: Stackpole Books, 2003, P. 69
Yellowstone River Valley. Far to the north in the Yellowstone River valley of Montana, on June 9, Lakota (probably Hunkpapa) killed a Colonel Smith of the 14th Wisconsin Regiment. Subsequently, they killed eleven men near Fort Benton on the Missouri River.
Nearly daily attacks on isolated outposts, stagecoach stations, and wagon trains continued throughout June and into early July. Several additional soldiers and civilians were killed, the raids reaching as far south as the South Platte River near Julesburg, Colorado.
Moonlight's mistakes
To respond to the raids, the commander at Fort Laramie, Colonel Thomas Moonlight, led a large force of 500 cavalry out of the fort to seek and punish the raiding Indians. He returned to the fort May 19, having found no Indians. In the words of a soldier, Moonlight "was hunting for them in [the] opposite direction [from] where their trail led."McDermott, p. 58
On May 26, 1865, Moonlight hung two minor Oglala leaders, Two Face and Black Foot. A white woman, Lucinda Ewbanks, and her small child were discovered living in pitiful condition among the Oglala bands. They had been kidnapped by Cheyenne almost a year earlier and sold to the Oglala band of Two Face and Black Foot. Moonlight ordered the two Oglala hung.McDermott, pp. 60-62 George Bent and others tell the story differently. Bent said the two Oglala ransomed the woman from the Cheyenne and brought her into the fort as a peace gesture. Moonlight, however, arrested and hung them, an action which Mrs. Ewbanks apparently protested. Experienced civilians at the fort warned Moonlight of repercussions. Their bodies, and that of a Cheyenne, were left hanging from the gallows for months for all visitors to the fort to see.Hyde, 208; Johnson, Dorothy M. "The Hanging of the Chiefs" Montana: The Magazine of Western History, Vol. 20, No. 3 (Summer 1970), pp 60-69
On June 3, the army fearing that the 1,500 Lakota, mostly Brulé, and Arapaho living near Fort Laramie, might become hostile, decided to move them about 300 miles east to Fort Kearny in Nebraska. The Indians protested that Fort Kearny was in the territory of their traditional enemies, the Pawnee. Moreover, they feared, with reason, there would be no food for them at Fort Kearny. The army insisted and the Indians, with an escort of 138 cavalrymen under Captain William D. Fouts, departed Fort Laramie on June 11. The soldier's mistreatment of Indian women and children caused the Lakota to turn hostile. The young Oglala warrior, Crazy Horse, slipped into the camp the night of June 13 and persuaded the Indians to flee the soldiers. The next day, near present-day Morrill, Nebraska, most of the Indians refused to accompany the soldiers and began crossing the North Platte River, assisted by Crazy Horse and a band of Oglalas on the other side. Attempting to stop them, Fouts and four soldiers were killed.Ambrose, p. 157; McDermott, pp. 70-73
Informed of the disaster, Moonlight departed Fort Laramie with 234 cavalry to pursue the Indians. He traveled so fast that many of his men had to turn back because their horses were spent. On June 17, near present-day Harrison, Nebraska, the Lakota raided his horse herd and relieved him of most of his remaining horses. Moonlight and many of his men had to walk 60 miles back to Fort Laramie. He was severely criticized by his soldiers for being drunk and not setting a guard on his horses. On July 7, Moonlight was relieved of his command and mustered out of the army.McDermott, pp. 73-75
The Platte River bridge was a key crossing point of the North Platte River for wagon trains of emigrants traveling the Oregon and Bozeman Trails. The Indians especially wanted to halt traffic on the Bozeman Trail which led through the heart of their hunting territory. The bridge had been constructed in 1859 and was almost 1,000 feet long and 17 feet wide."Platte River Fords" http://wyshpo.state.wy.us/trailsdemo/platteriverfords.htm, accessed 8 Nov 2012 On the south side of the river was the military post and stockade, staffed by 100 soldiers, a dozen or more armed civilians, a few Shoshoni scouts, and an office of the Overland Telegraph Company. The soldiers were low on ammunition.