It protects a large remnant of Atlantic Forest, and includes a system of lagoons rich in species of native fish.

The Rio Doce State Park is in the southwest of Minas Gerais, 248 kilometres (154 mi) from Belo Horizonte, in the Vale do Aço region.

[4] This is a system of forty natural lagoons including the 6.7 square kilometres (2.6 sq mi) Lagoa Dom Helvécio, with a depth of up to 32.5 metres (107 ft).

[4] Creation of the park was first suggested in the early 1930s by Dom Helvécio Gomes de Oliveira, Archbishop of Mariana.

[7] Exotic species of fish such as Tucunaré (Cichla), piranha and oscar (Astronotus ocellatus) have caused changes to the food chain.

[4] Mammals include the capybara (Hydrochoerus hydrochaeris), South American tapir (Tapirus terrestris), Black capuchin (Sapajus nigritus), Black-fronted titi monkey (Callicebus nigrifrons), lowland paca (Cuniculus paca), Gray brocket (Mazama gouazoubira"") and common agoutis, and endangered species such as jaguar (Panthera onca), solitary tinamou (Tinamus solitarius) and the Northern muriqui (Brachyteles hypoxanthus).

[2] Birds species include the Green-backed trogon (Trogon viridis), Ornate hawk-eagle (Spizaetus ornatus), Southern mealy amazon (Amazona farinosa), dusky-legged guan (Penelope obscura), Rufous-vented ground cuckoo (Neomorphus geoffroyi), Red-ruffed fruitcrow (Pyroderus scutatus), Tanagers and Forbes's blackbird (Anumara forbesi).

[2] The main attraction is the Lagoa Dom Helvécio, also known as Bishop's pond, where visitors can swim, fish, and make boat trips.

There is a public beach on the bank of the lagoon at the end of the park road, 6 kilometres (3.7 mi) from the entrance, which may be used for swimming and sports fishing.