The Ouzoum or Ouzom is a left tributary of the Gave de Pau

Gave de Pau

The Gave de Pau is a river of south-western France and a left tributary of the Adour. It takes its name from the city Pau, through which it flows. The river is in length, and its source is at the Cirque de Gavarnie in the Pyrenees mountains....

, in the Southwest of France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, between the Génie longue and the Béez

Béez

The Béez, is a left tributary of the Gave de Pau, in Béarn , in the Southwest of France. It flows into the gave upstream from Pau, between the Ouzoum and the Luz.- Name :...

.

It flows into the Gave in Nay

Nay, Pyrénées-Atlantiques

Nay is a commune in the Pyrénées-Atlantiques department in south-western France.It lies in the former province of Béarn.-Geography:The land of the commune are crossed by the Gave de Pau and one of its tributaries, the Béez-Place names:...

, upstream from Pau.

Name

Historical graphies were oscillating between the voiced -s- and the unvoiced -ss-: Oson (1441), Osom, Osson, Ozon (1538), le Lozon (1581), l'Ouson (1585).

This name could be related with the Pyrenean

Pyrenees

The Pyrenees is a range of mountains in southwest Europe that forms a natural border between France and Spain...

 hydronym

Hydronym

A hydronym is a proper name of a body of water. Hydronymy is the study of hydronyms and of how bodies of water receive their names and how they are transmitted through history...

 Ousse

Ousse

Ousse is a commune in the Pyrénées-Atlantiques department in south-western France.-References:*...

.

Geography

The valley of the Ouzoum is separated in two distinct parts by a 9-km-long narrow pass.
The villages located in the upper part of the valley (Arbéost

Arbéost

Arbéost is a commune in the Hautes-Pyrénées department in south-western France.-References:*...

 and Ferrières

Ferrières, Hautes-Pyrénées

Ferrières is a commune in the Hautes-Pyrénées department in south-western France.-References:*...

) belong to the Hautes-Pyrénées

Hautes-Pyrénées

Hautes-Pyrénées is a department in southwestern France. It is part of the Midi-Pyrénées region.-History:...

 and have relationships with the Val d'Azun, on the other side of the mountain.
On the other hand, the lower part of the valley, close to Pau, is Béarn

Béarn

Béarn is one of the traditional provinces of France, located in the Pyrenees mountains and in the plain at their feet, in southwest France. Along with the three Basque provinces of Soule, Lower Navarre, and Labourd, the principality of Bidache, as well as small parts of Gascony, it forms in the...

ese (Pyrénées-Atlantiques

Pyrénées-Atlantiques

Pyrénées-Atlantiques is a department in the southwest of France which takes its name from the Pyrenees mountains and the Atlantic Ocean.- History :...

).

The Ouzoum rises at Cap d’Ouzom ('head of Ouzom'; 1 131 m), in the Litor Circus dominated by the Grand Gabizos (2 692 m). This circus is in relation with the Val d'Azun through the Col du Soulor

Col du Soulor

Col du Soulor is a high mountain pass in the Pyrenees in France, linking Argelès-Gazost with Arthez-d'Asson. It connects the Ouzom and Arens valleys.The road is occasionally used in the Tour de France cycling race.-Tour de France:...

 (1 474 m) and with the Ossau Valley

Ossau Valley

The Ossau Valley is a valley of the French Pyrénées, in the Pyrénées-Atlantiques département.- Administration :...

 through the Aubisque Pass

Col d'Aubisque

The Col d'Aubisque is a mountain pass in the Pyrenees 30 km south of Tarbes and Pau in the department of the Pyrénées-Atlantiques , in the Aquitaine region of France....

 (1 709 m) .

After the basin of Ferrières

Ferrières, Hautes-Pyrénées

Ferrières is a commune in the Hautes-Pyrénées department in south-western France.-References:*...

, the Ouzoum flows through a narrow pass bordered by steep limestone slopes. The valley widens after Arthez-d'Asson

Arthez-d'Asson

Arthez-d'Asson is a commune in the Pyrénées-Atlantiques department in south-western France.Created at the end of the 18th century from Asson, it is enclaved into this other commune.-References:*...

.

Its hydrographic regime is pluvionival.

Départements and towns

• Hautes-Pyrénées
  Hautes-Pyrénées
  Hautes-Pyrénées is a department in southwestern France. It is part of the Midi-Pyrénées region.-History:...
  
  : Arbéost
  Arbéost
  Arbéost is a commune in the Hautes-Pyrénées department in south-western France.-References:*...
  
  , Ferrières
  Ferrières, Hautes-Pyrénées
  Ferrières is a commune in the Hautes-Pyrénées department in south-western France.-References:*...
  
  
• Pyrénées-Atlantiques
  Pyrénées-Atlantiques
  Pyrénées-Atlantiques is a department in the southwest of France which takes its name from the Pyrenees mountains and the Atlantic Ocean.- History :...
  
  : Asson
  Asson
  Asson is a commune in the Pyrénées-Atlantiques department in south-western France.-References:*...
  
  , Arthez-d'Asson
  Arthez-d'Asson
  Arthez-d'Asson is a commune in the Pyrénées-Atlantiques department in south-western France.Created at the end of the 18th century from Asson, it is enclaved into this other commune.-References:*...
  
  , Igon
  Igon
  Igon is a commune in the Pyrénées-Atlantiques department in south-western France.-References:*...
  
  , Nay
  Nay, Pyrénées-Atlantiques
  Nay is a commune in the Pyrénées-Atlantiques department in south-western France.It lies in the former province of Béarn.-Geography:The land of the commune are crossed by the Gave de Pau and one of its tributaries, the Béez-Place names:...
  
  .