Bestselling author David Grann drew very little attention when he arrived in Pawhuska during the summer of 2015 to begin research for his latest writing project.

“Nobody really knew anything about him, at first,” Osage County Hitorical Museum resource specialist Joyce Lyons said. “He said he was from The New Yorker, but that didn’t make much of as big impact, either.”

In time, however, as Grann spent day after day and then weeks at local and area museums, the diligence of the staff writer for The New Yorker magazine began to impress those around him.

“He was just so thorough about everything that, eventually, you couldn’t help but believe in what he was working on,” Lyons said.

A year later, the book Grann was working on — entitled “Killers of the Flower Moon: The Osage Murders and the Birth of the FBI” — started drawing major publicity. Last spring, Hollywood’s heavyweights lined up to put in bids for movie rights to Grann’s still-unnpublished book about the Osage “Reign of Terror” murders.

When movie-rights auction ended, Grann’s Osage project had drawn the highest bid in history — approximately $5 million. The cat was now out of the bag about the hard-working magazine writer who had been a frequent Pawhuska visitor.

“By then, everybody knew that he was very serious and accomplished,” Lyon added. “We are glad to have been able to help him and we’re very excited about his book.”

Lyon said Grann also made a positive impression when he expressed how much he missed his wife and children during his researching forays.

Kathryn Redcorn said her first contact with Grann was when he walked into the Osage Nation Museum, where she was (then) the director, and began talking about his Osage project.

“There are so many aspects of that story,” Redcorn said of the tribal tragedy. “He was interested in knowing everything about it. He wanted to talk to people who knew about any of those different aspects.”

Redcorn said Grann made numerous visits to Pawhuska and Osage County over the next few years.

“He attended several of our tribal dances so he could talk to some of people who were going to be there,” Redcorn added. “Even though he was looking into a very sad time in our history, we still tried to help him as much as we could.”

Grann was back in Pawhuska and Osage County less than two weeks ago, traveling with a CBS Sunday Morning News crew to document his book project in places where the events actually occurred. The footage has not yet aired.

The official release date for “Killers of the Flower Moon” was Tuesday. The 352-page hardcover is published by Doubleday. Described by reviewers as a “gripping true-crime narrative,” Grann’s book on the Osage Reign of Terror takes a close look at the investigations conducted by the agency that soon became known as the Federal Bureau of Investigation.

Grann will be make another local visit a few days after the book is released. He is to be back in town for a book-signing event from 10 a.m. to 2 p.m. April 29, at The Water Bird Gallery, 134 E. 6th St. The gallery is located across the street from the Pawhuska Post Office. Persons wishing to order a copy of the book for the signing can call the gallery at 918-2879129.

April 30, Grann is scheduled for a book-signing at TheTallChief theater in Fairfax. The Osage County Historical Society Museum, 700 Lynn Ave., is selling Grann’s book, as well as several others about the Osage murders. (During these upcoming visits, Grann will reportedly be accompanied by his family.)

Grann’s latest book release is coinciding with the release of a major movie adaption of his previous book, The Lost City of Z — based on another 1920s true story about the search for an ancient civilization along the Amazon River. Growing from an article Grann did for The New Yorker in 2006, Lost City was turned into a book in 2009.

“The Lost City of Z: A Tale of Deadly Obsession in the Amazon” told the story of the legendary British explorer Percy Fawcett who, in 1925, disappeared with his son in the Amazon while looking for the Lost City of Z. For decades, explorers and scientists have tried to find evidence of both his party and the Lost City of Z. More than 100 people perished or disappeared seeking Fawcett. Grann made his own journey into the Amazon, revealing new evidence about how Fawcett died and showing that Z may have indeed existed.

Drawing parallels between the Grann’s two books, one reviewer wrote: “In The Lost City of Z, (Grann) took readers deep into the jungles of the Amazon, tracing the steps of a vaunted explorer who went missing without a trace in 1925. In his new book, “Killers of the Flower Moon: The Osage Murders and the Birth of the FBI,” Grann explores a real-life monstrous crime that has become a footnote in United States history, despite its far-reaching implications.