The Pike's Peak gold rush was the boom in gold prospecting and mining in the Pike's Peak Country of western Kansas Territory and southwestern Nebraska Territory of the United States that began in July 1858 and lasted until roughly the creation of the Colorado Territory on February 28, 1861. An estimated 100,000 gold seekers took part. The dramatic but temporary influx of migrants and immigrants came to the Southern Rocky Mountains. The prospectors provided the first major White American population in the region.