# Travel >> Types of Travel >> Ski Trips

Peopling of the Americas: Migrations Across Beringia

How Many Migrations from Siberia to Alaska?

The peopling of the Americas occurred via the Bering Land Bridge (Beringia), exposed during the Last Glacial Maximum (LGM) when sea levels dropped ~120 m. Current genetic, archaeological, and paleoenvironmental evidence supports a **complex, multi-wave model**.

The Primary Window: ~25,000 – 13,000 Years Ago

Beringia was a vast, ice-free refugium (not just a bridge) connecting Siberia and Alaska. Humans occupied it for millennia (Beringian Standstill Hypothesis), isolated from Asian populations, before moving south into the Americas.

At Least Three Major Genetic Waves

First Americans (Ancestral Native Americans): Single founding population split from East Asians ~25–20 kya. Entered Americas south of ice sheets ~16–15 kya (coastal route likely). Gave rise to **all** indigenous populations south of the Arctic. Clovis culture (~13 kya) is a descendant manifestation.
Paleo-Eskimo / Saqqaq / Dorset: Separate migration ~5,000–4,000 years ago from Siberia. Spread across Arctic North America to Greenland. Genetically distinct from First Americans. Replaced by Thule.
Thule / Inuit (Ancestral Inuit/Yupik): Migration ~1,000–800 years ago from Alaska across Arctic. Ancestors of modern Inuit, Yupik, Iñupiat. Replaced Dorset culture.
Na-Dene / Athabaskan: Possible distinct wave ~5,000–3,000 years ago (linguistic/genetic links to Yeniseian languages in Siberia). Ancestors of Navajo, Apache, Tlingit, Athabaskans.

Nuances

Coastal vs. Ice-Free Corridor: Early migration likely used a Pacific coastal route (kelp highway) before the interior ice-free corridor opened (~13.8 kya).
Back-Migration: Gene flow *from* Americas back to Siberia occurred (e.g., Eskimo-Aleut ancestry in Siberia).
Not "Waves" in Simple Sense: Continuous gene flow, isolation, and admixture in Beringia over millennia; "waves" are analytical constructs from population genetics.