The 1689 Treaty of Nerchinsk eliminated Russia’s right to use the river and areas around the banks of the river were jointly administered by the 2 countries. In 1858, the Treaty of Aigun negotiated by Nikolai Nikolaevich Muravyov (soon-to-add Amursky to his name) gave Russia a river route from inland Siberia to the Pacific. As the 10th longest river in the world with a length of 1755 miles (2825 km), the Amur River now forms 1000 miles (about 1600 km) of the border between China and Russia.
Providing habitat to both subtropical Asian fish, like the snakehead and Chinese Carp, and Arctic Siberian fish, like pike and Siberian salmon, the Amur also grows the Kaluga sturgeon -- it’s largest fish, which can reach lengths of 18 feet (5.6 meters) and a weight of up to 2200 pounds (almost 1000 kg)! The largest undammed river in the Eastern Hemisphere and third largest in the world, the Amur is home to some of the most species rich wetlands and temperate forests in the world. The Amur River Basin is home to the Siberian tiger and the Far Eastern leopard, and its wetlands provide an enticing stopover point for many species of migrating birds, including Japanese cranes and white storks.
Not only does the Amur provide Russia with a route to the ocean, but it also contains placer gold. With about 200 tributaries, the Amur river is ice free during the months of May to November.
For photos and video check out the Amur river slide show.
Check out The Treasure of Nikolai Nikolaievich: Adventures on the Amur #1
Sources: https://en.wikipedia.org/wiki/Amur_River
https://www.worldatlas.com/articles/where-does-the-amur-river-flow.html
http://www.waterdatabase.com/rivers/amur-river/
http://www.socialstudiesforkids.com/articles/geography/amurriver.htm