Sand Creek Massacre Site National Park

On April 28, Sand Creek Massacre National Historic Site was made the most recent National Park in the USA. It is the site of the massacre of nearly 160 Cheyenne and Arapaho on November 29, 1864. At dawn that day, a force of some 700 volunteers in a Colorado regiment attacked a peaceful village of Cheyenne and Arapaho Indians camped along Sand Creek in southeastern Colorado Territory. The Sand Creek Massacre National Historic Site, situated on over 12,000 acres in southeast Colorado, "recognizes the significance of the massacre in American history and its ongoing significance to the Northern and Southern Cheyenne and Arapaho tribes."

See http://www.nps.gov/sand/index.htm