In 1590, the would-be governor of a colony meant to be one of England’s first outposts in North America discovered that more than 100 settlers weren’t on the small island where he left them.

More than 400 years later, the question of what happened to those settlers, who landed on Roanoke Island, off the coast of modern North Carolina, has grown into a piece of American mythology, inspiring plays, novels, documentaries and a tourism industry in the Outer Banks.

Stories have taken root that the colonists, who left no clear trace aside from the word “Croatoan” carved on a tree, survived somewhere on the mainland, died in conflict with Native Americans or met some other end.

A new book about the colonists, “The Lost Colony and Hatteras Island,” published in June and citing 10 years of excavations at nearby Hatteras Island, aims to put the mystery to bed. The book’s author, Scott Dawson, a researcher from Hatteras, argues that the Native people who lived there took in the English settlers and that historical records and artifacts can end the debate.

“Basically, the historical evidence says that’s where they went,” said Mark Horton, an archaeologist at the University of Bristol, in England, who worked with Mr. Dawson. Dr. Horton acknowledged that there was no “smoking gun” but said that with everything in context, “it’s not rocket science.”

Historians and archaeologists not involved in the recent research on Hatteras were more skeptical, saying that the evidence was inconclusive and that they wanted to see peer-reviewed work. They also said the argument was not new: The idea that the Croatoans, as the Native people on Hatteras were called, adopted at least some of the settlers has long been considered plausible.

“Sure, it’s possible — why wouldn’t it be?” said Malinda Maynor Lowery, a professor of history at the University of North Carolina at Chapel Hill. “People don’t get lost. They get murdered, they get stolen, they get taken in. They live and die as members of other communities.”

Dr. Maynor Lowery presented a similar possibility in her 2018 book on the history of the Lumbee people, the descendants of dozens of tribes in a wide region including eastern North Carolina. Despite violence by the English against Croatoan villagers, she wrote, the settlers probably took refuge with them.

“The Indians of Roanoke, Croatoan, Secotan and other villages had no reason to make enemies of the colonists,” she wrote. “Instead, they probably made them kin.”

The English landed into a complicated fray of conflict and shifting alliances, said Lauren McMillan, a professor at the University of Mary Washington in Fredericksburg, Va.

“They’re all interfighting, and these different groups are trying to use the English against one another,” she said. “The Croatoans perhaps saw the English as a powerful ally and sources of valuable new things.”

Dr. Maynor Lowery, who is Lumbee, added that the “lost colony” story is itself based on the incorrect premise “that Native people also disappeared, which we didn’t.”