Mari El (Марий Эл; Марий Эл; Мары Эл), officially the Mari El Republic, is a republic of Russia. It is in the European Russia region of the country, along the northern bank of the Volga River, and is administratively part of the Volga Federal District. The republic has a population of 696,459 (2010 Census). Yoshkar-Ola is the capital and the largest city.
Mari El is one of Russia's ethnic republics, established for the indigenous Mari people, a Finnic nation who have traditionally lived along the Volga River and Kama River. The plurality of the republic's population are ethnic Russians (47.4%) and Mari (43.9%), with minority populations of Tatars and Chuvash. The official languages are Russian and Mari. Mari El is bordered by Nizhny Novgorod Oblast to the west, Kirov Oblast to the north, Tatarstan to the east, and Chuvashia to the south.
The Republic is located in the eastern part of the East European Plain of Russia, along and mostly to the north of the Volga River. The swampy Mari Depression is in the west of the Republic, contrasted by hillier landscapes in the east where the highest point of the Republic (at ) is located. The Republic borders with Kirov Oblast in the north and east, the Republic of Tatarstan in the southeast and south, the Chuvash Republic in the south, and with Nizhny Novgorod Oblast in the west and north.
There are 476 rivers in the Republic, with the Volga and its tributaries being the major water arteries. Most rivers are considered to be minor— wide and deep—and usually freeze between mid-November and mid-April. There are over 700 lakes and ponds; many located in the swampy areas and having areas of less than and depths between . Lake Yalchik, occupying , is the largest by area, while Lake Tabashinskoye is the deepest. Swamps cover large areas— and up to —and usually freeze in December. While swamps tend to be shallow, with an average depth of , they are impassable in fall and spring due to flooding.
Climate is moderately continental, with moderately cold and snowy winters and warm and often rainy summers.