Anybody liking the works of Bob Nolan sung by others really ought to listen to reissues of the original Sons of the Pioneers' recordings, many still available on CD.
For the record, "Blue Prairie" was written by Tim Spencer, Bob Nolan's singing mate. Nolan helped in putting the finishing touches on the song, according to the liner notes on Empty Saddles, MCA-1563 (vinyl) by Laurence J. Zwisohn. Bob is given a co-writing credit on this album. The album contains 14 songs from 1935/36, including "I'm an Old Cowhand (From the Rio Grande)" by that great cowboy songwriter, Johnny Mercer(!).
The Sons were together for so long [is there still an incarnation] that it is interesting to hear versions of many of their songs recorded years apart when musical tastes and group personnel had changed.---John