What does Michael Shepherd's poem mean?

Question

We are like salmon, swimming back upstream;
Leaping against waterfalls that thwart,
Cut and bruised; but strong; our only dream
Return to source; no thought save source of thought;
And in that fight, our iron age turns to bronze,
And we to heroes, in a war of soul,
As nature seeks the nature it had once;
Though wholly lost, remembering the whole.
We silver salmon, sparkling as the sun
Shines on our fierce and loving enterprise:
To rear our children where the world is one;
The source remembered, nature's greatest prize.
The golden age is ageless in its gleam
And we, like salmon, swimming back upstream.

Answer 1

The stream is a metaphor for life, and the progression of ages a sort of literary vehicle, if not metaphor, then allegory, for our "progress" toward our goal, which is to return to our origin.

Where did you get this? Can you add some of your own thoughts in the comments section?

Answer 2

I think it's about us people. And how life kind of is except in he is explaining it through nature.