Great interview. McPhee says gathering facts and writing nonfiction (as opposed to more self-generated fiction stuff) is like going from the grocery store to the kitchen:

I always say to my classes that it’s analogous to cooking a dinner. You go to the store and you buy a lot of things. You bring them home and you put them on the kitchen counter, and that’s what you’re going to make your dinner out of. If you’ve got a red pepper over here—it’s not a tomato. You’ve got to deal with what you’ve got. You don’t have an ideal collection of material every time out. […]

Once I’ve written the lead, I read the notes and then I read them again. I read them until they’re coming out my ears. Ideas occur, but what I’m doing, basically, is looking for logical ways in which to subdivide the material. I’m looking for things that fit together, things that relate. For each of these components, I create a code—it’s like an airport code. If a topic is upstate New York, I’ll write UNY or something in the margin. When I get done, the mass of notes has some tiny code beside each note. And I write each code on an index card.

That’s laying it all out where he can look at it. It’s a technique he got from his high school writing teacher. One cool thing he found is that when you get the structure set, you can let the juxtapositions do some storytelling for you. In Encounters with the Archdruid, for example:

The whole book had thirty-six components. What I ended up with was thirty-six three-by-five cards, each with a code word. Some of these things are absolutely dictated by the story of the journey down the Colorado River. But the choices are interesting where it’s not dictated, like the facts of David Brower’s life.

I knew where I was going to start, but I didn’t know the body of the thing. I went into a seminar room here at the university, and I laid the thirty-six cards out on the table. I just looked and looked at them. After a while I was looking at two cards: Upset Rapid, which is a big-time rapid in the Colorado River, and Alpinist. In Upset Rapid, Brower doesn’t ride the rapid. Why doesn’t he ride the rapid? His answer to Floyd Dominy is, “Because I’m chicken.” That’s a pretty strong scene. What next? Well, there are more than seventy peaks in the Sierra Nevada that were first ascended by David Brower, hanging by his fingernails on some cliff. “Because I’m chicken”? This juxtaposition is just loaded with irony, and by putting the Alpinist right after Upset Rapid, in the white space between those two sections there’s a hell of a lot of stuff that I don’t have to say. It’s told by the structure. It’s all crackling along between those two things. So I put those two cards side by side. Now there are thirty-four other parts there on the table.

Paris Review – The Art of Nonfiction No. 3, John McPhee