The Trail Creek Caves, on the Seward Peninsula, are at what would have been the eastern coastal margin of Beringia — elevated above the Beringian plain, overlooking what was then the lake-dotted lowland of the eastern Beringian coast.

If the founding population during the standstill period was preferentially distributed in the coastal and near-coastal zones of the Beringian landmass, the Seward Peninsula would have been part of that preferential zone.

The Trail Creek child, living 9,000 years ago on the Seward Peninsula, was alive thousands of years after the standstill period would have ended — after the dispersal into the Americas had occurred and after the land bridge had submerged.

But her Ancient Beringian ancestry may reflect the genetic legacy of the standstill period — the specific genomic profile that developed in the Beringian population during the millennia of isolation, and that was carried forward by the Ancient Beringian branch even as other aspects of population history changed around it.