That's a very old Ballad Index entry. I have many more references, and a suggested author, now:

Zack, the Mormon Engineer

DESCRIPTION: Zack, the Mormon engineer, has a wife in every town along the D&RG, and so refuses to change lines.
AUTHOR: S. L. Samson?
EARLIEST DATE: 1932 (Briegel, 44 Old Time Mormon and Far West Songs, according to Lingenfelter/Dwyer/Cohen-SongsOfAmericanWest)
KEYWORDS: marriage railroading humorous train
FOUND IN: US(Ro)
REFERENCES (7 citations):
Cheney-MormonSongs, pp. 179-181, "Zack, the Mormon Engineer" (2 texts, 1 tune)
Botkin/Harlow-TreasuryOfRailroadFolklore, p. 444, "Zack, the Mormon Engineer" (1 text, 1 tune)
Greenway-FolkloreOfTheGreatWest, pp. 265-266, "Bishop Zack, the Mormon Engineer" (1 text)
Lingenfelter/Dwyer/Cohen-SongsOfAmericanWest, pp. 76-77, "Bishop Zack, the Mormon Engineer" (1 text, 1 tune)
Cohen-AmericanFolkSongsARegionalEncyclopedia2, p. 604, "Bishop Zack, the Mormon Engineer" (1 text)
DT, ZACKMORM*
ADDITIONAL: Tristram P. Coffin and Hennig Cohen, _Folklore in America: Tales, Songs, Superstitions, Proverbs, Riddles, Games, Folk Drama and Folk Festivals_, Doubleday, 1966, p. 88, "Bishop Zack" (1 text)
Roud #4761
RECORDINGS:
L. M. Hilton, "Zack, The Mormon Engineer" (on Hilton01, ClassRR)
Art Thieme, "Zack, The Mormon Engineer" (on Thieme03)
NOTES [56 words]: Said to be based, loosely, on the life of one Zack Black who worked on the Denver and Rio Grande railroad. The tune is loosely based on "Oh, Susanna."
Of all the books I've checked, only Lingenfelter/Dwyer/Cohen-SongsOfAmericanWest lists the author as S. L. Samson, and they don't document it, so I've listed it with a question mark. - RBW
Last updated in version 6.6

File: BRaF444