About 240km upstream from Costa Marques, the Reserva Extrativista Pedras Negras has good opportunities for hiking, canoeing, and spotting rare orchids, macaws, toucans, caimans, deer and river dolphins. There are also a few rural villages, dedicated mostly to rubber and Brazil-nut harvesting, that can be visited.
The reserve is normally open from June 15 to November 15 only, due to heavy rainfall the rest of the year. The best months to go are August to November, when river beaches are exposed. From September, turtle-nesting sites can be observed. Visits to the reserve were suspended at the time of research. Check with IBAMA in Porto Velho for the latest.