I'm wondering when the last verse ("Dan's feet are sore ... ") was added.
Presumably that verse is also by Bob Nolan, but I DK if it was part of the original song and just left off of the original Sons Of Pioneers recording.

The song was written by Nolan 5 years before the 1941 SOP recording, and it was recorded by Dude Martin that year (1936).

Also, Wikipedia and other sites currently describe Dan as a "mule."
I've always assumed he was a horse - probably because so many horses were named "Dan" -- but do we really know what sort of animal Nolan conceived him to be?




Cptsnapper,
Apparently Joni Mitchell (and maybe others who covered this song) rewrote some of the lyrics.   I wonder if those alternative lyrics you remember were the work of Joni or another artist who modified Nolan's original ones.



FWIW, here is a partial list of recordings of "Cool Water:

Dude Martin - 1936
The Sons Of The Pioneers - 1941
Bob Nolan & The Sons of the Pioneers (feat. in the film "Along The Navajo Trail") - 1945
Jimmy Wakely & The Riders Of The Purple Sage (featured in the film "Saddle Serenade") - 1945
Bob Nolan & The Sons of the Pioneers (featured in the film "Ding Dong Williams") - 1946
Wesley Tuttle - 1947
Vaughan Monroe & The Sons Of The Pioneers - 1948
Nellie Lutcher - 1948
Jimmy Wakely (feat. in the film "Brand Of Fear") - 1949
Gene Autry - 1950
Billy May & His Orch. (vocal: Bob Morse) - 1953
Polly Bergen - 1958
Kate Smith - 1958
George Melachrino & His Orch. (Instr.) - 1958
Johnnie Ray - 1959
Marty Robbins - 1959
Jack Scott - 1960
The Browns - 1960
Frankie Laine - 1961
Eddy Arnold - 1961
Ramblin' Jack Elliott - 1962
Lorne Greene - 1962
Tex Ritter with Stan Kenton & His Orch. - 1962
Odetta - 1963
Slim Whitman - 1963
Patti LaBelle & The Bluebelles - 1963
Hank Snow - 1965
Tom Jones - 1967
Moe Bandy - 1982
Riders In The Sky - 1989
Michael Martin Murphy - 1995

Also recorded by:
Roy Rogers
Johnny Bond
Walter Brennan
Bill Black's Combo
Bing Crosby & The Andrews Sisters
Eddie Dean
Fleetwood Mac
Tennessee Ernie Ford
Frank Ifield
Burl Ives
Sleepy LaBeef
Norman Luboff Choir
Jack MarshallR
Rex Allen
Mills Brothers
Rooftop Singers
Cliffie Stone
Hank Williams
Kate Smith
Mason Williams
Boston Pops Orch.

I think Tex Ritter's recording is the one that stands out in my mind (in addition to the Sons Of The Pioneers).