Colin Monteath / Caribou (Rangifer tarandus) and Tsataan reindeer herders in winter camp, Hunkher Mountains, northern Mongolia

Bryan and Cherry Alexander / Grisha (right) and Gosha Vanuitto, Nenets reindeer herders, at their winter camp on the tundra in the South Tambey Gas Field, Yamal Peninsula, Siberia, Russia. February 2014.

Bryan and Cherry Alexander / Chukchi girls, with their family's ancestral clan mark painted in reindeer blood on their face, a ritual during the Chukchi 'Festival of the Young Reindeer' during which young reindeer are sacrificed....

Bryan and Cherry Alexander / Rainbow over a Khanty reindeer herders' camp by the Bolshaia Paipudyna River in the Polar Urals Mountains. Yamal, Western Siberia, Russia, Summer 2007.

Bryan and Cherry Alexander / Rainbow over Khanty reindeer herders' camp in the Polar Ural Mountains. Yamal, Western Siberia, Russia, Summer 2007.

Bryan and Cherry Alexander / Sun rises behind Reindeer / Caribou skin tents at a Nenets herders' winter camp. Yamal, Siberia, Russia, 1993.- 40 BELOW BOOK

Olga Kamenskaya / Nenet reindeer herders setting up camp, Nenets Autonomous Okrug, Arctic, Russia, July 2017.

Olga Kamenskaya / Dog with Mosquitos, in temporary reindeer herders' camp, Nenets Autonomous Okrug, Arctic, Russia, July

Olga Kamenskaya / Nenet herders camp, Nenets Autonomous Okrug, Arctic, Russia, July 2017

Bryan and Cherry Alexander / Spotted nutcracker (Nucifraga caryocatactes) feeding on reindeer meat at a winter herders' camp, Purovsky region, Yamal. Western Siberia, Russia

Eric Baccega / Woman carrying bag of snow, for water, to Nenet reindeer herders' camp on tundra. Yar-Sale district. Yamal, Northwest Siberia, Russia. April 2016.

Bryan and Cherry Alexander / The skins and meat from sacrificed young reindeer adorns the inside of a Chukchi Yaranga (tent) during the 'Festival of the Young Reindeer'. Iultinsky District, Chukotka, Siberia, Russia