Tverrvatnet[2] [tvær'vatne] is a lake in Rana Municipality in Nordland county, Norway.

The European route E12 highway passes along the northern and eastern shores of the lake between the town of Mo i Rana and the border with Sweden.

From the west, a brook from Fisktjønna ("the fish water") ends up as a tributary to Umskarbekken.

The Tverrvatnet farm (now called Tverrvassgården) was built on an important rallying point among the Ume Sami speaking population.

[3] Tverrvatnet farm was an important link of the trade between Sweden and Mo i Rana, before the opening on 13 August 1939 of the highway what was later named European route E12.

[4] The farm was of uttermost importance during the catastrophic year of hunger on the Swedish side of the border in 1867.