Its highest point is the 429 m (1,407 ft) high summit of the Kupol Vostok Pervyy (Купол Восток Первый) ice dome that covers part of the island.

[1] There are wide unglaciated areas on the northern and the southwestern shores.

Off Alger Island's southwestern shores lies Ostrov Matil'dy (Остров Матильды), a very small, barely 1 km (0.62 mi) long, island.

He named it after U.S. Secretary of War Russell A. Alger who had donated $250 to Wellman's expedition.

[2] The wintering site of the 1901 failed American Baldwin-Ziegler North Pole Expedition was on Alger Island.