The mystery of Roanoke Island may be one for the books. Two archaeological teams have dug up new evidence pointing to the fate of English colonists who mysteriously vanished from the North Carolina island 425 years ago, National Geographic reports.

One collection of items appears to support the long-held theory that some colonists moved to Hatteras Island, about 50 miles southeast of Roanoke. "The evidence is that they assimilated with the Native Americans but kept their goods," says chief archaeologist Mark Horton.

Among the Hatteras Island finds: a small bit of a slate writing tablet marked by the letter "M," a rapier hilt likely dating to the late 16th century, and pieces of iron, ingot, and stoneware apparently dating to the same period.

What's more, the name of a native American settlement on Hatteras Island—"Croatoan"—was found etched into a post in 1590 when all the colonists had vanished. For the second find, archaeologists used a map drawn by colony governor John White in 1585.

The map includes an "X" obscured by a patch and may have been a "'cover-up' ... to keep information from the public and from foreign agents," a historian told National Geographic two years ago.

The "X" marked a site on Albemarle Sound, an estuary in North Carolina, where archaeologists recently discovered dozens of pottery pieces that resemble others found on Roanoke Island.

So is this finally proof? Not really, because it's hard to date items precisely or know how they got there. "What we’ve found is tantalizing," a volunteer says.

"I would love to see some definitive evidence, but what we have is fragmentary.” (In other US history news: Archaeologists have pinpointed a key location in the Hatfield-McCoy feud.)

This article originally appeared on Newser: Roanoke Island Mystery May Finally Be Solved

More From Newser