Loir

The Loir is a river in central France. It is a left tributary of the Sarthe. It flows through two regions of France: Centre-Val de Loire and Pays de la Loire
The Eure-et-Loir and Loir-et-Cher departments are named after this river.
Geography.
The Loir is long. Its drainage basin covers .
Its average yearly discharge (volume of water which passes through a section of the river per unit of time) is at Durtal, Maine-et-Loire (1961 - 2017).
Average monthly discharge (m3/s) at Durtal
Course.
The Loir starts in the former province of "Perche", in the "commune" of Champrond-en-Gâtine, Eure-et-Loir department, Centre-Val de Loire region. It starts at an altitude of about .
The Loir flows, in general, to the southwest. It goes through the following regions, departments and "communes":
At its end, the Loir flows into the Sarthe river at the place called "Bec du Loir" ("beak of the Cher") in Briollay, Maine-et-Loire department, at of altitude.
Main tributaries.
The main tributaries of the Loir are:
Left tributaries:
Right tributaries: