I ran into a fifth grade schoolmate and we pieced the song together so i thought I'd share it.

ROLL ALONG WAGON TRAIN
    D                         G
Oh across the plains roll the wagon trains
       A7                     D
On the way to the gold fields far.
                                 G
Where the bobcat prowls and the coyote howl
          A7             D
And the herds of buffalo are.
(ch)
                               G          D
Roll along, roll along, roll along wagon train
                               G    A7       D
Roll along, roll along, roll along across the plain.

We will camp tonight at a pleasent site
and we'll sing to the banjo's strum.
To the fiddles squeal we will dance a reel
And be gay what ever may come
(ch)