The Rio Acre is a 680-kilometer river in central South America, flowing through Peru, Bolivia, and Brazil before joining the Purus River at Boca do Acre. Within Brazil, it passes through the state of Acre, including near the town of Xapuri, and continues into the state of Amazonas at its lower reaches. In the local Iñapari language, the river is known as Aquiry.

The river is navigable by boat from its mouth upstream to the confluence with the Xapuri River, a stretch of approximately 480 kilometers. During the wet season, which runs from January through May, water levels rise sufficiently to extend navigable passage beyond that point. Paddlers planning trips should factor this seasonal variation into route planning, as access to upper sections of the river is more practical during those months.

The Rio Acre Ecological Station, located in the municipalities of Assis Brasil and Sena Madureira, protects Amazon forest near the river's headwaters. The station is bounded to the north by an indigenous reservation and to the south by the river itself, and was established specifically to preserve the headwater region.

Historically, the Rio Acre served as a significant transportation corridor in the late 19th century, when rubber tree forests were discovered in the surrounding region. That legacy reflects the river's role as a practical artery through otherwise dense Amazonian terrain, a character it retains today across its lower navigable reaches.