Lesser Khingan is a mountain range in China's Heilongjiang

Heilongjiang

For the river known in Mandarin as Heilong Jiang, see Amur River' is a province of the People's Republic of China located in the northeastern part of the country. "Heilongjiang" literally means Black Dragon River, which is the Chinese name for the Amur. The one-character abbreviation is 黑...

 Province and the adjacent parts of Russia's Amur Oblast

Amur Oblast

Amur Oblast is a federal subject of Russia , situated about east of Moscow on the banks of the Amur and Zeya Rivers. It shares its border with the Sakha Republic in the north, Khabarovsk Krai and the Jewish Autonomous Oblast in the east, People's Republic of China in the south, and Zabaykalsky...

 and Jewish Autonomous Oblast

Jewish Autonomous Oblast

The Jewish Autonomous Oblast is a federal subject of Russia situated in the Russian Far East, bordering Khabarovsk Krai and Amur Oblast of Russia and Heilongjiang province of China. Its administrative center is the town of Birobidzhan....

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In China, the Lesser Khingan mountain range runs roughly from the northwest to the southeast and separates the valley of the Amur (Heilongjiang) River from that of the Nenjiang River. The mountain range then turns toward the east and north-east, entering Russia. The Amur/Heilongjiang, which is a border river, forms a gorge when crossing the mountain range.