This is the song somebody mentioned as being in a Roy Rogers movie - the movie was My Pal Trigger. Gene Autry also sang it ten years earlier in The Big Show, which featured a very young Roy Rogers in a bit part as a member of the Sons of the Pioneers.

OLD FAITHFUL
(Michael Carr/Jimmy Kennedy)

Old faithful, we rode the range together
Old faithful in every kind of weather
When your round up days are over
There'll be pastures white with clover
For you, old faithful pal of mine.

Hurry, up old fellow,
'Cause the moon is yellow tonight
Hurry, up old fellow
'Cause the moon is mellow and bright.

There's a coyote howlin' to the moon above
So carry me back to the one I love
Hurry up, old fellow
'Cause we gotta get home tonight.