Everybody who has read Ian Frazier's short humor writings -- collected in "Dating Your Mom" (1986) and "Coyote v. Acme" (1996) -- knows he is a funny guy. But he's not funny when he talks about the New Yorker, where he spent 21 years as a staff writer before pulling out in disgust at what Tina Brown had done to the magazine. He still feels bitter towards S.I. Newhouse, the tycoon who bought the New Yorker in the mid-'80s, dumped its legendary editor, William Shawn, replaced him with Alfred A. Knopf editor in chief Robert Gottlieb and then, five years later, dumped Gottlieb for Brown.

But the reach of Shawn -- who died in 1992 -- is long, and Frazier's new book, "On the Rez" (out this month from Farrar, Straus and Giroux), bears the stamp of the editor's influence in its meandering, essayistic, more or less unclassifiable eccentricity. ("Everything has to have some kind of purpose now," Frazier laments of the direction that magazine writing has taken. "And for a lot of great nonfiction, there's just no way to say why this is interesting, why you care about this subject.")

"On the Rez" is about American Indians -- specifically about the Oglala Sioux on the Pine Ridge Reservation in southwestern South Dakota. The book is stuffed with fascinating material -- about the casinos that have recently made several tribes rich; about Red Cloud, the rival of Crazy Horse, whom Frazier wrote about in his first full-length nonfiction book, "Great Plains" (1989); about Indians and alcohol, a subject that, as he explains below, he had a hard time figuring out how to approach (there is a lot of drinking in his earlier books, but by the time he started "On the Rez" he'd quit); about a heroic Oglala basketball star named SuAnne Big Crow, who died in a car crash shortly before her 18th birthday; and especially about his bumpy friendship with a mercurial Oglala named Le War Lance. The writing is (predictably) wonderful, but it may strike anyone who's been bewitched by the daredevil virtuosity of Frazier's earlier work as surprisingly straightforward and even subdued. The often somber subject matter, he explained to me, called for a simpler, less antic style.

As a "Talk of the Town" reporter in the '70s, Frazier hung out with a talented group of young New Yorker writers that included Jamaica Kincaid, Mark Singer, George W.S. Trow and the late Veronica Geng (a close friend who died in 1997). In 1982 he left his lower Manhattan loft for an A-frame house outside Bigfork, Mont., and began the research for "Great Plains." He moved back to New York for the writing of "Family" (1994), and then, in 1995, he moved his family back to Montana -- this time to Missoula -- to research "On the Rez."

The drive from Missoula to Pine Ridge is 780 miles. As I was reading I lost track of how much ground Frazier covered in all his trips back and forth. (His books would be very different if he didn't have a driver's license.) This summer he and his family returned to the East Coast. I interviewed him at their house in New Jersey on a freezing night a couple of weeks ago.

Has Le War Lance seen the book?

I sent him a copy.

And have you spoken to him since then?

Oh yeah, we've talked several times. I think he read it, but I don't know -- he hasn't said anything. The Atlantic sent him 10 copies of the issue with the excerpt from the book, and I said, "Well, what did you think?" He said two of them were stolen and the other ones he sold.

It's a peculiarly structured book. Is the structure something you came to as you were writing it, or did you know before you sat down what shape it was going to have?

I knew where I wanted to start, and I knew where I wanted to end. I knew that the moment where SuAnne Big Crow is in the gym at Lead [S.D.] was emotionally powerful. And then, when she wins the championship -- I knew that was a very powerful moment; it caused a big celebration on Pine Ridge and brought together all of the different factions who had fought during the Wounded Knee days in the '70s. I knew that it made sense for the part about SuAnne to be toward the end. But other than that I didn't have an awful lot of sense of structure.

All my nonfiction books kind of have an essay structure. You go from here to here to here more or less as your curiosity takes you, and you just have confidence that at each place you're going to be somewhere. But an essay is best if it's not outlineable.

This one, though, has the most cohesive subject.

Right. In "Family" I was running in every direction, trying to talk about all of these different things -- the history of America, the history of Protestantism, what happened in my family and what happened with my father's company. After "Family" I wanted to have something a little narrower. The tighter the focus, the easier it is to know what fits and what doesn't.

In "On the Rez," although you include a lot of direct exposition about Native American life and culture, the subject of alcoholism is something you keep circling around but never approach directly. Was that deliberate?

I couldn't think of anything to say that wasn't what other people said all the time. "Oh well, they're just genetically -- something or other." "They have such and such that makes them this way." I couldn't find a sentence like that that I like. I've heard white people say, "Well, they have this problem," which, even if it's true, I wasn't comfortable saying. So I didn't go in that direction. I didn't do any research on it, either.

There are all these explanations. The frontier was a culture of alcoholism -- no question about it. White frontier people and Indians shared this bond. It's like when you meet somebody you don't know very well and you say, "Let's have a drink." Once you've had two or three drinks you're the best buddies in the world. I think there was an awful lot of that -- "Well, he might look different, but he gets just as drunk as I do."

And I had another theory. Imagine you lived in a house and people moved in next door and they were the worst people you'd ever met in your life; your dog died and your plants died and your kids died ... Wouldn't you maybe just get really drunk and hope that they would go away?

I stopped drinking, and that is really important to me in the book. I don't know if the reader will notice it, but it meant a lot to me to have this idea of why sobriety is important. In the book I say, "If the devil exists, he's probably sober." And I really believe that. That's a huge change from the '60s. In the '60s, the devil was sober, so therefore -- get drunk. Now I would say the devil's sober, so you better watch it.

Your style has changed since "Great Plains." In that book the virtuosity is on the surface; you're really tap-dancing in front of people, having a great time and showing off. The virtuosity in this book is much more under the surface; it doesn't call attention to itself. Was that a conscious shift?

Well, "Great Plains" was done for the New Yorker. It came after years of writing for the "Talk of the Town" department, where the point was to do something splashy and funny and to catch people's attention -- especially when you knew that the rest of the magazine was very likely to be much weightier. I knew that "Great Plains" wasn't going to outweigh "The Fate of the Earth." The point was to be kind of flashy -- and also to catch Mr. Shawn's attention.

Shawn thought that when I went out West I had gone nowhere. And I kept getting that from a lot of people: "What is out there?" "I looked out the airplane window and there's nothing there." I was trying to say, "Oh, yes, there's definitely something here," and so I was more stylistically extreme.

The subject matter of "On the Rez" called for me to be more subdued. I felt a bit more cowed by a subject as heavy as death and suffering -- it just wasn't the place for doing something flashy and surprising. And I didn't find myself coming up with those stylistic ideas where you get the reader expecting something and then go completely in the other direction -- like in my profile of Heloise ["Nobody Better, Better Than Nobody," 1983], where I say, "I had not been in Texas long before I started having millions of insights about the difference between Texas and the rest of America. I was going to write these insights down, but then I thought -- nahhh."

I had that feeling -- that I knew people were expecting one thing and I would try to fake them out -- up until the last few years. I guess without the New Yorker, I became much more conservative. Also, as I've gotten older, I've come to believe that you should be able to tell a story with the words that are at hand. And that's how I do it.

When you were at the New Yorker, you were part of a group of promising young writers. Do you feel unmoored from that society now?

Well, just before you showed up, the fax machine was printing out a piece of Jamaica Kincaid's. Back then if I had an idea I would walk across the hall and talk to her about it. Now, we talk on the phone, or we see each other; we are still really close. I don't feel unmoored. I talk to Mark Singer pretty regularly. I miss Veronica Geng terribly.

I was infatuated: I loved the New Yorker. Shawn probably thought I was not a particularly loyal guy, because I moved to Montana and I got rid of my office while I was supposedly a staff writer, and I wouldn't sign a contract, for reasons I don't even remember. I found Shawn an oppressive figure and a great figure at the same time. If he was real close to you, you might get a little bit overwhelmed. Yet this guy was really a genius, and he created this work of art, and I wanted to participate in it without feeling like I'd fallen into some kind of Shawn rut. Anyway, it was a complicated relationship.

I think I would have continued there for my whole life if it had continued to be possible. When it fell apart, I was very angry. I was incredibly angry at Newhouse, and I still am. I got along OK with Bob Gottlieb -- I like Bob. And then Tina Brown was a drastic shelving off into nightmare horror.

I would never write for it again. I don't trust the people who own the magazine. I think they did badly by many people who worked for them. I saw what it did to people who were thought of as New Yorker writers and artists; it was impossible to scrape it off at the end.

My conclusion was that you will get your heart broken if you care about an institution. But if you're loyal to people and you really feel affection for them, then you can follow them. I'm writing for some people who are now at their third magazine since I started working for them. I like staying with people, and that has proved to be a better principle than just loving the New Yorker.

But it was really something to lose. I was at the New Yorker for 21 years. And I hate when it comes up: Every so often there's another book and you have to talk about it again.

I was going to ask.

It's like a divorce -- "Oh God, that's what my ex-wife is doing now?" You're always tied to it. At first I'm always resistant: I'm not going to talk about Renata Adler's book ["Gone: The Last Days of the New Yorker"]. I'm not, I'm not. And the next thing I know I'm talking about it.

Have you read it?

No. But I've talked about it. I've probably talked more words about it than are in it.

Will you continue writing for the Atlantic now that William Whitworth has been replaced as editor by Michael Kelly?

I hope I will continue. Bill Whitworth has urged people to. He was a lot nicer than I would have been. I was also angry about that -- but it's possible that this will be a better change than the New Yorker change was. You're always in a situation of hoping. We were hoping at the New Yorker for God knows how many years before we realized that Tina was not going to -- that it wasn't going to work.

Are you still planning a book about Russia?

Yes, that's what I'm working on, a book about Siberia. I was in the city of Provideniya last summer, on the Chukchi Peninsula, which is just across from Nome, Alaska. It's an incredibly cool place -- my favorite place to go.

Do you love the cold?

I do, especially now that it's so rare. I love to get up where you can still see winter. There's so much in Siberia -- obviously it's a huge subject, but I'm always encouraged when I find a subject that has a great genre. And travels in Siberia is an enormous genre; it was very much so in the 19th century and also in the 20th.

Are you working on your Russian?

Yes, I am. It's OK if they talk slowly. And I'm reading. The people in Siberia are incredibly literate people. In 1998 I did a translation of "It Happened Like This," a book by Daniil Kharms, a wonderful, really funny Russian writer who was killed by Stalin in 1942. My favorite piece by him is "Anecdotes from the Life of Pushkin." It's just seven completely ridiculous anecdotes. The first Russian sentence I really learned is from one of them: "Pushkin loved to throw rocks"-- "Pushkin liobil kidatsya kamnyami."

When I was in Siberia we had guides -- people who lived on the tundra -- and we were doing something that involved throwing rocks into a burlap sack to make a big weight. As I was throwing the rocks in I said, "Pushkin liobil kidatsya kamnyami."And everybody laughed. They got it -- they knew the piece. And I thought, God, they know Daniil Kharms! A hundred miles west of Nome, Alaska, they know Kharms!