Absolutely!

The musicality of the tune doesn't come through in 6/8. Maybe that's why Tozer (?) changed it.

In the 1880s, it wouldn't be surprising if by altering the time he thought he was not only improving the song but getting it back to "how it once must have been."

As sung by Capt. Albert H. Rasmussen, rec. by Alan Lomax April, 11, 1955: http://research.culturalequity.org/get-audio-detailed-recording.do?recordingId=12581 :

Heavily accented as indicated by italics. Note “Missouree,” not “Missourye.”

Oh SHENanDO’! I have to leave thee!
And aWAY, you rolling river!
Oh, SHENanDO! I have to leave thee!
AWAY I’m going to roam,
‘Cross the WIDE Missouri!

Oh, SHENanDO’, I love your daughter!
And aWAY, you rolling river!
Oh, SHENando’, I love your daughter!
AWAY I’m going to roam,
‘Cross the WIDE Missouri!