This collection was first published in 1980 by Sierra Club Books, and it remains an important volume. I've used it as a text in environmental studies courses a few times and would do so again. Bly's essays are useful and provocative and the (mostly) historically organized texts provide a wide range of accessible and important "pieces of thinking" - to borrow a phrase from Bringhurst. It is full of poems that have stayed with me and that I come back to again and again. Below is one favorite.
A pale morning in June 4AM
the country roads still greyish and moist
tunnelling endlessly through the pines
a car had passed by on the dusty road
where an ant was out with his pine needle working
he was wandering around in the huge F of Firestone
that had been pressed into the sandy earth
for a hundred and twenty kilometers.
Fir needles are heavy.
Time after time he slipped back with his badly balanced
and worked it up again
and skidded back again
travelling over the great and luminous Sahara lit by clouds.
Translated by Robert Bly
More Jacobsen in English in
Copper Canyon Press.