William McGaa

William W. McGaa (17 April 182415 December 1867) was a mountain man and one of the early figures in the history of the Colorado settlement of St. Charles (now called Denver). Born in Scotland, he immigrated to the United States and was living with the Arapaho under the name Jack Jones by the time of the Colorado Gold Rush.

McGaa claimed an upper-class ancestry. He declared he was the son of the Lord Mayor of London and had a family estate in Scotland, Glenarm.

William Larimer worked with McGaa, who camped on the bank of Cherry Creek, to steal the land for the town of St. Charles from the local Native Americans, the official owners of the land as recognized in 1851 by the Fort Laramie Treaty. This was possible because McGaa 'claimed' various native wives as property and therefore represented that he had the authority to make the land transfer.

His son, William Denver McGaa, with wife Jennie Adams is noted as being the first child, both white and Native American, born in Denver, on March 8, 1859.