Cape is constructed on the basis of >120 radiocarbon ages. Since 2007, several research projects were funded by the National Science Foundation, led by John F. Hoffecker, Owen K. Mason and Claire M. Alix. The dunes contain a remarkable record of architectural history and cultural change in relation to climate change. The earliest occupations at the Cape ca. 2500 calibrated BCE record the first maritime adaptions along the north Alaska coast. In 2011, archaeologists found metal artifacts at Cape Espenberg, including a cast bronze buckle, very likely smelted in East Asia, either Siberia or farther South. The finds were discovered adjacent to a house inhabited by the Birnirk people, the presumed ancestors of the modern Inuit. The metal objects were not locally cast, based on metallurgical analyses (X-ray fluorescence) by Purdue University Assistant Professor H. Kory Cooper. The metal was deposited at Cape Espenberg at least 500 years before sustained contact with Europeans in the late 1700s. While the metal is not directly dated, the "buckle" was attached to a leather strap that yielded a calibrated radiocarbon date of ca AD 1200. References http://westerndigs.org/asian-metal-found-in-alaska-reveals-trade-centuries-before-european-contact/ https://instaar.colorado.edu/news-events/instaar-news/john-hoffeckers-team-unearths-first-prehistoric-cast-bronze-artifact-found/ Espenberg Landforms of Northwest Arctic Borough, Alaska