Powell, as Sorcha points out, it's in The Willie Nelson Deluxe Anthology, 1994 Warner Bros. Publications, Inc., Words/music by Johnny Bush, copyright 1972, 1976 by Full Nelson Music. All rights administered by Windswept Pacific Entertainment Co. d/b/a Longitude Music Co.The Anthology will run you about $22.95 at the local Barnes & Noble or Borders.
And yes, it's very much copyrighted--no duplication of any kind permitted.
Don't know if it will help at all, but Cowpie (http://www.roughstock.com/cowpie/)--(sorry, can't find the destructions for a clicky thing) has the words and chords.
Lin