Bolshoy Patom

{{about||the rural locality|Bolshoy Patom (village)}}

{{Infobox river

| name = Bolshoy Patom

| other_name = Большой Патом

| image = Bolshoy Patom-ONC D-7.jpg

| image_caption = Bolshoy Patom river course map section

| source1_location = Patom Highlands

| source1_coordinates = {{coord|58|50|24|N|115|26|45|E|source:wikidata-and-enwiki-cat-tree_region:RU}}

| source1_elevation = {{convert|842.5|m|abbr=on}}

| mouth = Lena

| mouth_location =

| mouth_coordinates = {{coord|60|02|23|N|117|18|10|E|source:wikidata|display=it}}

| mouth_elevation = {{convert|145|m|abbr=on}}

| progression = {{RLena}}

| subdivision_type1 = Country

| subdivision_name1 = Russia

| length = {{convert|570|km|mi|abbr=on}}

| discharge1_avg = {{convert|350|m3/s|abbr=on}}

| basin_size = {{convert|28400|km2|sqmi|abbr=on}}

| pushpin_map = Russia Irkutsk Oblast

| pushpin_map_size =

| pushpin_map_caption= Mouth location in Irkutsk Oblast, Russia

}}

The Bolshoy Patom ({{langx|ru|Большой Патом}}), "Big Patom", is a river in Irkutsk Oblast, Russia. It is the 11th longest tributary of the Lena with a length of {{convert|570|km|mi}} and a drainage basin area of {{convert|28400|km2|mi2}}.{{GVR|240620|Река Бол. Патом}}[http://bse.sci-lib.com/article128723.html Большой Патом]; Great Soviet Encyclopedia in 30 vols. — Ch. ed. A.M. Prokhorov. - 3rd ed. - M. Soviet Encyclopedia, 1969-1978.(in Russian)

Bolshoy Patom village is located by the riverbank in its lower course. Tourists visit the Bolshoy Patom river mainly for rafting and kayaking. In the International scale of river difficulty the Bolshoy Patom is a Class III and IV river. There are picturesque white limestone cliffs flanking a number of stretches of the Bolshoy Patom.[https://water-rf.ru/%D0%92%D0%BE%D0%B4%D0%BD%D1%8B%D0%B5_%D0%BE%D0%B1%D1%8A%D0%B5%D0%BA%D1%82%D1%8B/1069/%D0%91%D0%BE%D0%BB%D1%8C%D1%88%D0%BE%D0%B9_%D0%9F%D0%B0%D1%82%D0%BE%D0%BC Water of Russia - Большой Патом]

==Course==

The Bolshoy Patom is a right tributary of the Lena. It has its sources in the Patom Highlands, roughly {{convert|257|km|mi}} north of Bodaybo. The river flows first in an approximately western direction across the highland area within a gorge cut into the plateau bedrock. Near the slopes of the northern end of the Kropotkin Range it bends and flows roughly northwards with many rapids. Then it bends slightly and flows northeastwards parallel to the Lena that skirts the highlands further to the west.

The area named "Forty Islands" (Сорок Островов) is located near the confluence of the Satalakh, {{convert|377|km|mi|abbr=on}} from the mouth, where the river splits into channels, forming islands in between.

In its last major bend, the Bolshoy Patom heads eastwards. The river channel widens and the flow slows down in its last {{convert|250|km|mi|abbr=on}} stretch across a wide floodplain.

Finally the Bolshoy Patom meets the right bank of the Lena near at the border of the Sakha Republic (Yakutia), {{convert|2334|km|mi}} from its mouth. The town of Macha lies just a few miles downstream from the confluence.Google Earth

The Bolshoy Patom has several tributaries that are over {{convert|100|km|mi|abbr=on}} long. The largest are the Bolshaya Taimendra, Cheloichen, Tonoda and Khaverga from the right; and the Tamper and Muoda from the left. There are 445 lakes in the river basin with a total area of {{convert|15.6|km2|sqmi|abbr=on}}. During spring floods it may overflow its banks and flood surrounding areas.

The river freezes between October and May. In its last stretch the Bolshoy Patom is navigable during the high-water period of the year.

valign="top" |File:Lena.svg