Who Lives in the Taiga on Pieces of Rotting Wood and Salt

Broad, shallow rivers
Can’t cut grand canyons,
But the snow-fed, small
Creek with its bone saw
That is what it does
And does what it is,
Chuckling as it goes,
Cut this mountain notch
Where the escaped wretch
Hid from the hellhounds,
Where lazy Rip slept,
Where the stone thrown down
By volcanoes, dunes,
And oceans let go.
Lower and lower
Past the last fossil
Past the first fossil,
Chuckling and narrow,
Cutting tomorrow,
Lost from the get go,
Lets us go, lets go.