[1][2] It was centered around the areas of Masuria, Powiśle and Warmia.

[1][3] On 25 September 1945, areas near its western border were incorporated into the Gdańsk Voivodeship, while the areas near its eastern border, to the Białystok Voivodeship.

[4] In December 1945, the Polish administration in Iławka was expelled by the Soviets, and the town, which was originally supposed to belong to Poland with the original border set one kilometer north of the town, was annexed to the Soviet Union.

[5] The Masurian District existed until 28 June 1946, when it was abolished and replaced with the Olsztyn Voivodeship.

[2] The head of the district was the attorney-in-fact Stanisław Piaskowski.