The main island is Matykil Island (Остров Матыкиль). It is 6 Km in length and has a width of 2.2 Km. All the other islands are much smaller. The highest point in Matykil is 700 m.
The other islands of the group are: Atykan (Остров Атыкан), Baran (Остров Баран), Khatemalyu (Остров Хатемалью) and Kokontse (Остров Коконце).
The Yam Islands are a home for the Steller sea lion and a variety of birds. Administratively the Yam Islands belong to the Magadan Oblast of the Russian Federation. They are also a part of the Magandskiy Zapovednik or protected bioregion of the Magadan area.