<P> Initially relations between participants in the Pike's Peak gold rush and the Native American tribes of the Front Range and the Platte valley were friendly . An attempt was made to resolve conflicts by negotiation of the Treaty of Fort Wise which established a reservation in southeastern Colorado, but the settlement was not agreed to by all of the roving warriors, particularly the Dog Soldiers . During the early 1860s tensions increased and culminated in the Colorado War and the Sand Creek Massacre where Colorado volunteers fell on a peaceful Cheyenne village killing women and children which set the stage for further conflict . </P> <P> The peaceful relationship between settlers and the Indians of the Colorado and Kansas plains was maintained faithfully by the tribes, but sentiment grew among the Colorado settlers for Indian removal . The savagery of the attacks on civilians during the Dakota War of 1862 contributed to these sentiments as did the few minor incidents which occurred in the Platte Valley and in areas east of Denver . Regular army troops had been withdrawn for service in the Civil War and were replaced with the Colorado Volunteers, rough men who often favored extermination of the Indians . They were commanded by John Chivington and George L. Shoup who followed the lead of John Evans, territorial governor of Colorado . They adopted a policy of shooting all Indians encountered on sight, a policy which in short time ignited a general war on the Colorado and Kansas plains, the Colorado War . </P> <P> Raids by bands of plains Indians on isolated homesteads to the east of Denver, on the advancing settlements in Kansas, and on stage line stations along the South Platte, such as at Julesburg, and along the Smoky Hill Trail, resulted in settlers in both Colorado and Kansas adopting a murderous attitude towards Native Americans, with calls for extermination . Likewise, the savagery shown by the Colorado Volunteers during the Sand Creek massacre resulted in Native Americans, particularly the Dog Soldiers, a band of the Cheyenne, engaging in savage retribution . </P> <P> The Dakota War of 1862 (more commonly called the Sioux Uprising of 1862 in older authorities and popular texts) was the first major armed engagement between the U.S. and the Sioux . After six weeks of fighting in Minnesota, led mostly by Chief Taoyateduta (aka, Little Crow), records conclusively show that more than 500 U.S. soldiers and settlers died in the conflict, though many more may have died in small raids or after being captured . The number of Sioux dead in the uprising is mostly undocumented, but after the war, 303 Sioux were convicted of murder and rape by U.S. military tribunals and sentenced to death . Most of the death sentences were commuted by President Lincoln, but on December 26, 1862, in Mankato, Minnesota, 38 Dakota Sioux men were hanged in what is still today the largest penal mass execution in U.S. history . </P>

What was the last major battle of the plains indian wars