Every year, thousands of reindeer migrate from Norway to Finland.

This year, a whopping 3,500 of them are making the trip, accompanied by dozens of Sami herders — indigenous Scandinavians traditionally linked to reindeer herding.

The journey begins in the Sami capital of Karasjok in northern Norway. The reindeer spend two months crossing icy plains, where temperatures can easily reach -15 degrees Fahrenheit.

Herder Jan Helmer Olsen took this footage with his drone, and said "My footage felt very special as nobody ever manages to see how the herd moves as one body from the air. It's [like] watching a huge flock of birds in flight."

Story and editing by Ben Nigh