The Morro dos Seis Lagos (Hill of the Six Lakes) Biological Reserve is in the municipality of São Gabriel da Cachoeira, Amazonas.

Highway BR-307 runs through the reserve, connecting the town of São Gabriel da Cachoeira to Cucuí on the Rio Negro near the point where the river enters Brazil.

[5] The Companhia de Pesquisas e Recursos Minerais (CPRM) claimed the mineral rights based on a concession and explorations that started in 1975.

[5] The Morro dos Seis Lagos Biological Reserve was created by Amazonas state decree 12.836 of 9 March 1990.

[7] In October 1997 a scheduled auction of the niobium reserve was cancelled due to pressure from the Brazilian Institute of Environment and Renewable Natural Resources, which objected to opening the mine since it is within two protected areas.

[4] Fauna include jaguar (Panthera onca), ocelot (Leopardus pardalis) and screaming piha (Lipaugus vociferans).