Here's another version, much closer to "Red River Valley."

THE BRIGHT SHERMAN VALLEY

From this valley they tell me you're leaving;
I will miss your bright eyes and sweet smile,
For you take with you all of the sunshine
That has lightened my path for awhile.
Do you think of the home you are leaving,
Of the parents so kind and so true?
Do you think of the fond heart you're breaking,
Of the girl who has loved you so true?

CHORUS
Just consider a while ere you leave me;
Do not hasten to bid me adieu;
Just remember the bright Sherman valley
And the girl who has loved you so true.

For a long time I've waited, my darling,
For the sweet words you never would say,
And at last my fond heart now is breaking,
For they tell me you're going away.
When you go from the scenes of this valley,
And they tell me your journey is through,
Just remember the bright Sherman valley
And the girl who has loved you so true.
(Chorus)


Notes:

THE BRIGHT SHERMAN VALLEY
No folk song has been more widely sung by all types of Americans than "Red River Valley"; no other has been claimed by so many regions. Residents of the valley of the Red River of the North call it their own. Residents of the Red River Valley of the South are just as certain it is a song about their river. Many Texans have told me it was "made up" at Sherman, Texas.
The truth is that the song was originally written about the Mohawk Valley of New York and called "In the Bright Mohawk Valley." It was composed and published as sheet music in the middle of the nineteenth century, and thus has been in oral circulation about a hundred years. Though the title has changed, both words and music have, strangely enough, remained remarkably faithful to the original.
In my early associations this was a "lonesome song." Negroes on chain gangs, in the bottomland cotton fields —or wherever they were set to work— sang it in a slow soft murmur as they labored. Whites sang it too, picking out the tune when they could on guitar or banjo. It formed a background for our lives and work even more realistically than it did for the Joads in the motion picture version of The Grapes of Wrath.

Source: Texas Folk Songs (William A. Owens, 1950), pp. 190-192

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This thread (click) has other versions of "Sherman Valley" - but none has the part that's giving you trouble, Roberto.