I heard this song as part of the soundtrack to a programme on BBC World about navigating the Northwest Passage.
^^^ Northwest Passage
Words and music: Stan Rogers
(Recorded by Tom Lewis on Poles Apart)
Chorus:
F-o-r just one time I would take the Northwest passage,
To find the hand of Franklin reaching for the Beaufort Sea,
Tracing one warm line through a land so wide and savage,
And make a Northwest passage to the sea.

Westward from the Davis Strait 'twas there 'twas said to lie,
The sea route to the Orient for which so many died,
Seeking gold and glory, leaving weathered, broken bones,
And a long forgotten, lonely cairn of stones.

Three centuries thereafter I take passage overland,
In the footsteps of brave Kelso, where his 'sea of flowers' began,
Watching cities rise before me, then behind me sink again,
This tardiest explorer, driving hard across the plain.

And through the night, behind the wheel, the mileage clicking West,
I think upon McKenzie, David Thompson and the rest,
Who cracked the mountain ramparts and did show a path for me,
To race the roaring Fraser to the sea.

How then am I so different from the first men through this way?
Like them I left a settled life, I threw it all away,
To seek the Northwest passage at the call of many men,
To find there but the road back home again.

And if should be I come again to loved ones left at home,
Put the journals on the mantle, shake the frost out of my bones,
Making memories of the passage, only memories after all,
And hardships there the hardest to recall.

Curiously enough, it was sung to the same tune as "Wolfe" by the Albion Band on their Light Shining album, so perhaps Ashley borrowed the tune as part of the natural progression of things?