A big swathe of the Namadgi National Park is to reopen to the public from Monday.
It means that two-thirds of the park will now be open to the public. Only the worst-hit core where the fire started at the end of January remains too damaged to allow people back in.
The park's visitor centre will remain closed while repair work is completed.
"We can go back into the majestic mountains again," park manager, Brett McNamara, said.
"As Canberrans, we've been through a lot in the last six months and connecting with nature is something we all need to do."
He said it was time to get off social media and to pitch a tent in the park's campgrounds and look at the stars.
The four month wait for wide public access has been because Mr McNamara and a bevy of ecologists and other experts have been assessing the damage done by the fire which tore through 80 per cent of the park.
They have been examining how much damage the influx of destructive animals and invasive weeds have caused since the fire. A feral deer monitoring program has been underway within the Cotter River catchment.
There has also been a lot of clearing away of dangerous burnt trees from public roads and walking tracks.
Efforts have been made to try to reduce the amount of ash in creeks and to protect threatened areas, particularly bogs and fens.
The cleanliness of the alpine bogs in the park is crucial to the water supply for Canberra. They act as a giant sponge soaking in water high in the mountains and then releasing it further into the catchment area for the city's water supply.
When the area was being surveyed as the potential site for the Australian capital more than a century ago, the bogs were a clincher in the decision to choose what became Canberra.
The ACT's Environment Minister, Mick Gentleman, said: "I'm pleased to welcome visitors back to the Corin and Naas/Boboyan Road precincts, along with some of my favourite areas of the park including Gibraltar Falls, Corin Dam, Settlers Walking Track, and Square Rock."
Two campgrounds (Woods Reserve and Mount Clear) will reopen. Work has been done on the Woods Reserve site to "lessen the impact of any future bushfire."
"Dedicated camper trailer spaces are now available at Woods Reserve for the growing demand for this type of recreational camping," Mr Gentleman said.
The areas which will remain closed for the foreseeable future are in the Orroral Valley where the fire which burnt 3,350 hectares started. The re-opened two thirds are to the north and south.
"Honeysuckle, Orroral Valley and Bimberi Wilderness Area remain closed as major works are required to restore public access roads, walking trails, low-level crossings and fire trails," Mr Gentleman said.
"The green shoots of recovery that can be seen across the burnt area are a reminder that our landscape is resilient."