Kamchatka Peninsula,peninsula in far easternRussia, lying between theSea of Okhotsk on the west and thePacific Ocean andBering Sea on the east. It is about 750 miles (1,200 km) long north-south and about 300 miles (480 km) across at its widest; its area is approximately 140,000 square miles (370,000 square km). Two mountain ranges, the Sredinny (“Central”) and Vostochny (“Eastern”), extend along the peninsula and rise to 15,584 feet (4,750 metres) inKlyuchevskaya Volcano. Thetrough between these mountain chains is occupied for much of its length by theKamchatka River. Of the 127 volcanoes on the peninsula, 22 are still active, as are a number of geysers and hot springs. Most of the activevolcanoes lie along a fault line on the eastern flank of the Vostochny Range. The western coastlands of the Kamchatka Peninsula form a low plain crossed by many rivers and with extensive swamps, while the eastern coast is an alternation of broad gulfs and cliffed mountainous peninsulas. A small geothermal-power station using underground steam operates near the southern end of the peninsula.

The climate of theKamchatka Peninsula is severe, with prolonged, cold, and snowy winters and wet, cool summers. Most of Kamchatka istundra supporting mosses and lichens, with thickets of Kamchatkaalder. Sheltered lowlands—notably the valley of the Kamchatka River, which separates the mountain chains—are inbirch or larch forest, with poplar andwillow in wetter areas.

The only important economic activity is fishing, especially crabbing, around the coasts. Agriculture is limited; some cattle andreindeer are kept. The main centre is the city and port ofPetropavlovsk-Kamchatsky, which is located on the southeastern coast of the peninsula. Most of the inhabitants are Russian, withindigenousKoryak, Chukchi, andKamchadal.