The Aldan River is the second-longest tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the Lena River

Lena River

The Lena is the easternmost of the three great Siberian rivers that flow into the Arctic Ocean . It is the 11th longest river in the world and has the 9th largest watershed...

 in the Sakha Republic in eastern Siberia

Siberia

Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

. The river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 is 2,273 km (1412 mi) long, of which around 1,600 km (994 mi) is navigable. It was part of the River Route

Siberian River Routes

Siberian River Routes were the main ways of communication in the Russian Siberia before the 1730s, when roads began to be built. The rivers also were of primary importance in the process of Russian exploration and colonisation of vast Siberian territories...

 to Okhotsk

Okhotsk

Okhotsk is an urban locality and a seaport at the mouth of the Okhota River on the Sea of Okhotsk, in Okhotsky District, Khabarovsk Krai, Russia. Population: 4,470 ;...

. In 1639 Ivan Moskvitin

Ivan Moskvitin

Ivan Yuryevich Moskvitin was a Russian explorer, presumably a native of Moscow, who led a Russian reconnaissance party to the Pacific Ocean, becoming the first Russian to reach the Sea of Okhotsk....

 ascended the Aldan and Maya River

Maya River

Maya River is a river in Khabarovsk Krai and Sakha, Russia. It is a right tributary of the Aldan River of the Lena basin. The length of the river is 1053 km. The area of its basin 171,000 km². The Maya River freezes up in late October and stays under the ice until May. The Yudoma River is one of...

s and crossed to the Ulya River

Ulya River

Ulya River is a river in northern Khabarovsk Krai in Russia. The length of the river is 325 km, the area of its drainage basin is 15,500 km². The Ulya originates in the Dzhugdzhur Mountains, flows northeast parallel to the coast and turns east to reach the Sea of Okhotsk about 100km southwest of...

 to reach the Sea of Okhotsk

Sea of Okhotsk

The Sea of Okhotsk is a marginal sea of the western Pacific Ocean, lying between the Kamchatka Peninsula on the east, the Kuril Islands on the southeast, the island of Hokkaidō to the far south, the island of Sakhalin along the west, and a long stretch of eastern Siberian coast along the west and...

.

It rises in the Stanovoy Mountains southwest of Neryungri

Neryungri

Neryungri is the second largest town in the Sakha Republic, Russia. Population: Municipally, the town is incorporated as Neryungrinsky Municipal District ....

, then northeast past Aldan

Aldan, Russia

Aldan is a gold-mining town and the administrative center of Aldansky District of the Sakha Republic, Russia. Population: -Geography:Aldan is situated in the Aldan highlands, about south of the republic's capital of Yakutsk in the Aldan River basin, on the stream Orto-Sala near its mouth in the...

 and through Tommot

Tommot

Tommot is a town in Aldansky District of the Sakha Republic, Russia, located on the Aldan River southwest of Yakutsk and southwest of Aldan. Population: -Geography:...

, Ust-Maya

Ust-Maya

Ust-Maya is an urban locality and the administrative center of Ust-Maysky District of the Sakha Republic, Russia, located at the confluence of the Maya and Aldan Rivers, southeast of Yakutsk. Population:...

, Eldikan

Eldikan

Eldikan is an urban locality in Ust-Maysky District of the Sakha Republic, Russia, located on the right bank of the Aldan River, northeast of Ust-Maya, the administrative center of the district. Population:...

 and Khandyga

Khandyga

Khandyga is an urban locality and the administrative center of Tomponsky District of the Sakha Republic, Russia, located on the Aldan River. Population:...

 before turning northwest and joining the Lena near Batamay.

The river's main tributaries are the Amga River

Amga River

Amga River is a river in Sakha , Russia. It is the biggest tributary of the Aldan River, which it joins a few miles west of Khandyga. The length of the river is . The area of its basin is 69,300 km². The Amga River freezes up in the first half of October and stays under the ice until May....

, Uchur River

Uchur River

Uchur River is a river in Khabarovsk Krai and Yakutia in Russia, a right tributary of the Aldan River . The length of the river is 812 km. The area of its drainage basin is 113,000 km². The Uchur freezes up in November and breaks up in May. Its main tributaries are the Uyan, Tyrkan, Gonam, and...

 and Maya River

Maya River

Maya River is a river in Khabarovsk Krai and Sakha, Russia. It is a right tributary of the Aldan River of the Lena basin. The length of the river is 1053 km. The area of its basin 171,000 km². The Maya River freezes up in late October and stays under the ice until May. The Yudoma River is one of...

. Its basin

Drainage basin

A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 is known for gold

Gold

Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

 and for Cambrian

Cambrian

The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...

 fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s.