His adoptive parents were John Mitchell Clark Collier and Izella Grace Swift Collier. In 1900 they were in Kickapoo and South Wichita Townships in the Lincoln area of Oklahoma Territory. By 1910 they were in Colorado and John is listed with them as their son. He was born November 11, 1903.
My grandmother says he was a boy old enough to remember his last name and birth date and that he was born in Blackfoot, Idaho. She says her father told her it happened in Oklahoma for certain. So I'm assuming at least 5 years old when it happened, but that's my assumption.