Edith Fowke, ed., 1973, "The Penguin Book of Canadian Folk Songs," includes a version of "The Red River Valley," no. 52, p. 124-125, with note as follows (in part): "This is probably the best known folk song on the Canadian prairies. --- later research indicates that it was known in at least five Canadian Provinces before 1896, and was probably composed during the Red River rebellion of 1870 ('The Red River Valley Re-examined', Western Folklore, 23, 163). Later versions are short and generalized but the early form told of an Indian or half-breed girl lamenting the departure of her white lover, a soldier who came west with Colonel Wolseley to suppress the first Riel Rebellion. Mrs Fraser's text is very similar to the earliest known versions, and Barbeau gives another traditional version from Calgary in "Come A-Singing."
The version, with music (chorus same as verses) and chords is presumably the one from Mrs. Fraser. No dates given for any version.

Lyr. Add: THE RED RIVER VALLEY (Fowke)

b 4/4 From this (F)valley they say (C7)you are (F)going; F
I shall (F)miss your bright (F)eyes and sweet (C7)smile, C
For a- (F)las you take (F)with you the (Bb)sunshine Gm
That has (C)brightened my (C7)pathway a- (F)while.

Chorus
Come and sit by my side if you love me,
Do not hasten to bid me adieu,
But remember the Red River Valley
And the girl who has loved you so true.

For this long, long time I have waited
For the words that you never would say,
But now my last hope has vanished
When they tell me that you're going away.

Oh, there never could be such a longing
In the heart of a white maiden's breast
As there is in the heart that is breaking
With love for the boy who came west.

When you go to your home by the ocean
May you never forget the sweet hours
That we spent in the Red River Valley,
Or the vows we exchanged 'mid the bowers.

Will you think of the valley you're leaving?
Oh, how lonely and dreary 'twill be!
Will you think of the fond heart you're breaking
And be true to your promise to me?

The dark maiden's prayer for her lover
To the spirit that rules o'er the world;
His pathway with sunshine may cover,
Leave his grief to the Red River girl.

Sounds like a parlor song. It does not sound as though it developed from the people involved.
There are many Metis (half-breed) in the west, who are still on Metis reserve land. Some rights are still undetermined. They were set apart from the Indians and from the whites. Hudson Bay Traders sometimes took Indian women as wives. In some cases the marriage took, and the family, which may have been given land by the Bay, eventually moved into the Canadian population, others were drawn into the Metis settlements which were in the center of the Riel Rebellion, and may have either kept the Metis way of life, or eventually moved into the general population. In many cases, the white trader or voyageur moved on, leaving the woman and children to the welfare of Indian or Metis relatives. The story is complex.
Some Canadian families with these origins recognize their native blood, others do not. Some with roots from the British Isles prefer the term 'country' in place of Metis but those with French roots use the term Metis.
Most military men went back to where their units came from.

An interesting complication is that a percentage of the active voyageurs were hired from Hawai'i. Not all returned although they mostly had contract limits.