That wouldn't seem necessary to me, since John A. Lomax published it in his Cowboy Songs and Other Frontier Ballads, which was first printed in 1910. My "revised edition" was published in 1938. He offers no credit to an informant in this book, however. Still, it's considered a cowboy variant of "The Wagoner's Lad," and I'll offer the text as it was first published:

I'm a rambler and a gambler, and a long ways from home,
If the people don't like me, they can sure leave me alone.

Oh! it's dark and a-rainin', and the moon gives no light;
My pony won't travel a dark road at night.

Go put up your pony and give him some hay,
Come take your seat by me so long as you stay.

My pony is hungry nor he won't eat your hay;
I'll go to Wyomin', I'll graze on the way.

When you get to Wyomin' a letter you'll see,
If you get into trouble, just write and tell me.

I use' to have a sweetheart, her age was fourteen,
She was the flower of Belton, and the rose of Saline;

Her parents were against me, and now she is the same,
If I'm on your book, love, please blot out my name.

The song has Anglo-Irish roots, to be sure, but this publication gives the melody as Peggy Seeger sang it, and is clearly her primary source, although I remember several other verses, such as:

There's changes in the ocean, there's changes in the sea,

There's changes in my true love. There ain't no change in me.

And Harry Tuft, out in Denver, added:

When I got to Wyoming, no letter I found.
The first snow was a-fallin', Lord, it covered the ground.

Is the big question "did the Clancys learn it from Peggy?" I have no answer. But I'd bet against it.

Sandy