Located well above the Arctic Circle, the site includes the mountainous Wrangel Island (7,608 km2), Herald Island (11 km2) and surrounding waters. Wrangel was not glaciated during the Quaternary Ice Age, resulting in exceptionally high levels of biodiversity for this region.
Criterion (iv): Wrangel Island Reserve has the highest level of biodiversity in the high Arctic. The island is the breeding habitat of Asia's only snow goose population, which is slowly making a recovery from catastrophically low levels. The marine environment is an increasingly important feeding ground for the gray whale migrating from Mexico (some from another World Heritage site, the Whale Sanctuary of El Vizcaino). The islands have the largest seabird colonies on the Chukchi Sea, are the northernmost nesting grounds for over 100 migratory bird species including several that are endangered such as the peregrine falcon, have significant populations of resident tundra bird species interspersed with migratory Arctic and non-Arctic species and have the world's highest density of ancestral polar bear dens. Wrangel Island boasts the largest population of Pacific walrus with up to 100,000 animals congregating at any given time at one of the island's important coastal rookeries. As Wrangel Island contains a high diversity of habitats and climates and conditions vary considerably from one location to another, total reproductive failure of a species in any given year is practically unheard of. Given the relatively small size of the area, this is very unusual in the high Arctic.
Currently, 417 species and subspecies of vascular plant have been identified on the island, double that of any other Arctic tundra territory of comparable size and more than any other Arctic island. Some species are derivative of widespread continental forms, others are the result of recent hybridization, 23 are endemic.
The number and type of endemic plant species, the diversity within plant communities, the rapid succession and mosaic of tundra types, the presence of relatively recent mammoth tusks and skulls, the range of terrain types and geological formations in the small geographical space, are all visible evidence of Wrangel's rich natural history and its unique evolutionary status within the Arctic. Furthermore, the process is continuing as can be observed in, for example, the unusually high densities and distinct behaviours of the Wrangel lemming populations in comparison with other Arctic populations; or in the physical adaptations of the island reindeers, where they may now have evolved into a separate population from their mainland cousins.
Evidence of a Neolithic camp inhabited by palaeo-Eskimo hunters of an ancient Eskimo culture of approximately 3,400 years ago are found in Krassin Bay on the south coast of Wrangel Island. Some of their prey species are known from the remains of woolly mammoth Mammuthus primigenius and bones and tusks of the pygmy woolly mammoth Mammuth primigenius wrangelensis, which lived on the island only some 7,000-3,700 years ago - 6,000 years later than the official extinction date. There were also furry rhinocerosCoelodonta antiguitatus, primeval bison Bison priscus and Prjewalski's horse Equus caballus przevalskii, remains of which are abundant on the island's plains. Herald Island was first seen in 1849; Wrangel Island was discovered by an American whaler in 1867 and named after the Russian navigator and explorer Ferdinand von Wrangel, who had searched for the island after learning of it from mainland natives and seeing northward-migrating birds. Russian settlement began in 1926, followed by military installations at Zvezdnyi on Somnitel'naya Bay, and reindeer herder settlements, later abandoned, but with many artefacts still well preserved.