It is navigable from the mouth until the Xapuri River (480 kilometres (300 mi)), even farther in the wet season from January until May.

The river was an important transportation artery at the end of the 19th century due to newly discovered rubber tree forests.

In 1899, the Bolivian government established a custom-house at Puerto Alonso, on the Acre river, for the collection of export duties on rubber, which precipitated a conflict with the Brazilian settlers, and finally brought about a boundary dispute between the two republics.

In July 1899 the "Acreanos" declared their independence and set up a republic of their own, but in the following March they were reduced to submission by Brazil.

The boundary dispute was finally settled at Petropolis on November 17, 1903, through the purchase by Brazil of the rubber-producing territory, south to about the ninth parallel.