History of character is unknown.
- Although this character was originally introduced during DC's Earth-One era of publication, their existence following the events of the 1985-86 limited series Crisis on Infinite Earths remains intact. However, some elements of the character's Pre-Crisis history may have been altered or removed for Post-Crisis New Earth continuity, and should be considered apocryphal.
- The designation of the Wyoming Kid as an Earth-One character in the pre-Crisis multiverse is arbitrary. His stories straddled the Earth-Two and Earth-One eras, and he never met any other established characters from either universe, so his home universe is hard to determine.
- The Wyoming Kid was established as a New Earth character in DC Universe Legacies #3.
- Western Comics
- Who's Who: The Definitive Directory of the DC Universe Vol 1 26 (Wyoming Kid biography page)
- 107 Appearances of William Polk (New Earth)
- 41 Images featuring William Polk (New Earth)
- Quotations by or about William Polk (New Earth)
- Character Gallery: William Polk (New Earth)
- Wyoming Kid at dccomics.com
- Wyoming Kid at Wikipedia.org
- Wyoming Kid biography page at the Unofficial Guide to the DC Universe