"We've pretty much opened up everything that wasn't burned," said Sherry Rollman, a spokeswoman for the agency.
The majority of the burn area remains closed, including the Angeles Crest (2) Highway, Big Tujunga Canyon Road and other access streets.
The fire was the largest in Los Angeles County history, destroying 250 square miles.
Two county firefighters were also killed while trying to defend their camp.
Rep. Adam Schiff was scheduled to testify Wednesday before the Senate Appropriations Subcommittee on the Interior, Environment and Related Agencies to call for a possible repeal of Forest Service policies prohibiting nighttime flights.
The policy has been criticized for potentially allowing the Station fire to grow out of control in the early days of the blaze.
In an announcement released Tuesday, forest Supervisor Jody Noiron said officials were making "hard choices" about how to allocate repair and recovery resources for the burn areas.
Forest officials have been developing a recovery plan that takes into account the mountainside ecosystems, including water, vegetation and wildlife, but access to some badly damaged sections could take longer to rehabilitate, Rollman said.
"It may take years for some of these areas to recover," she said.