The Ontario government announced Tuesday that the forest will retain its reserve status, which prohibits the commercial harvesting of old growth red pine.
However, exploration and development of existing mining claims and leases are still allowed.
The government says it made the decision based on the feedback it received during its consultation about the forest's future use.
Conservation organizations had lobbied the government to protect the forest, which they said was in peril more than 13 years after the province promised to protect its 300-year-old pines.
The government says maintaining the forest's reserve status will protect the environment and provide clarity for developers.