The short but intense Beringian summers, with their long days of sunlight and relatively dry, warm conditions, allowed a diverse and nutritious plant community to grow rapidly.

The absence of the insulating peat layer meant that the soil warmed more thoroughly in summer, extending the growing season for the grassland community.

And the diversity of the plant community — with multiple grass and forb species providing different nutrients at different times of the growing season — supported a diverse herbivore fauna that exploited different plant resources.

The rivers of eastern Beringia — the Bluefish, the Old Crow, the Porcupine, and their tributaries — were, during the Last Glacial Maximum, carrying substantial meltwater from the surrounding highlands where glaciation was occurring, even as the Yukon interior itself remained relatively ice-free.

These rivers provided reliable water sources, fish populations that could supplement the large-animal diet, and geographic corridors that could be followed by both animals and people moving through the landscape.