The book combines three long essays previously published in The New Yorker: "Atchafalaya", "Cooling the Lava", and "Los Angeles Against the Mountains".

In Vicksburg, Mississippi, a man recommended to McPhee that he research the efforts being undergone to control the debris sliding down from mountains into Los Angeles.

Due to the Mississippi's vital importance to industry, the Army Corps of Engineers constructed a control structure at the Atchafalaya's source to prevent this from occurring and to maintain the 30 percent drainage.

Los Angeles Times critic Jack Miles praised McPhee's "knack of presenting even the most ordinary folks in their best, most ingenious moments."

Ruess concluded that "McPhee's reports from the battlefronts are not as valuable as their implicit message that the control of nature is not nearly as important as knowing one's place in it.