Generations of Mohawk Indians have been “sky-walkers,” helping to construct some of the most famous features of New York City's skyline. They were first recruited to the trade by economic necessity, and later by a proud tribal tradition.

It's dangerous, awe-inspiring work, and ordinarily I wouldn't have any sense of what it's like to navigate such a dizzying position. Several years ago I got to know something about Indian sky-walkers, however, from the pages of an unforgettable novel by Sherman Alexie, titled “Indian Killer.”

I got the book, a dog-eared paperback with some passages underlined and notes in the margins, from Jose Gonzalez, a professor of English at the U.S. Coast Guard Academy in New London. You may have read about him recently, as he was named Poet of the Year by the New England Association of Teachers of English.

A native of El Salvador, Gonzalez had just gotten another award, for increasing multicultural awareness, when I interviewed him in 2003. Indian identity in one form or another has been news here for a long time, so I asked Gonzalez to recommend a book for me. He handed me “Indian Killer,” saying it was a gift.

At first I demurred, but I agreed to take it with the understanding that I would pass it on.

The hero, or anti-hero, is John Smith, a Spokane Indian — like Alexie — adopted as an infant by an infertile white couple and raised around Seattle, which during the book's timeline is terrorized by a serial killer who scalps white men.

John becomes a sky-walker, but what else he becomes depends, I think, a lot on the reader.

What fascinated me, aside from the novel itself, was the scribbling — not too heavy, not too much, some in pencil, some in ink — Gonzalez had left. At times I felt like I was reading the book in tandem with someone else.

What made all this especially intriguing was that I barely knew the other reader, and he had a perspective that was, while not inscrutable, very different from mine.

Gonzalez had underlined the passage, “Indians had become invisible, docile. John wanted to change that.”

Next to a passage in which a college student questions a non-Indian's ability to teach a class about the Indian experience, Gonzalez had written, “Does she have a point?”

I appreciated the previous book owner's insights, and was tempted to add some of my own. John's adoptive parents had, I felt, a genuine poignancy, as they tried — however haplessly — to do the right thing by exposing their brown-skinned son to Indian culture, all the while hoping that he wouldn't reject theirs.

In short, they wanted him to love them like they were his own. And if John grew up with a desperate sense of loss, his parents lived with a desperate fear of losing him.

Perhaps because on some level I felt the book wasn't truly mine, I refrained from writing in it. Looking back, however, I think it belonged to me, too.

I won't ever know what it means to be a sky-walker, traversing an iron beam high up in the sky, or to be an American Indian, traversing one of our nation's great historical divides.

But the next best thing to donning someone else's shoes can be reading — and writing — between the lines.