More than 80 percent of Department of Conservation visitor sites forced shut by wild weather in the North Island earlier this year have reopened.
Around 500 conservation areas, tracks, campgrounds, huts and heritage sites were closed due to damage, mostly in Northland, Auckland, Coromandel and Hawke's Bay.
The department's cyclone recovery director Dan Heinrich said the clean up was a massive task.
"Not all sites were damaged, but all required work to inspect them, clear slips, move fallen trees from tracks and do minor repairs to make them safe to reopen," Heinrich said.
He said a third of the remaining closed sites had major damage, and more poor weather was slowing repair work.
"We're continuing to work to clean up and repair damage at sites and replace lost infrastructure such as fences and trap networks to restore previous levels of protection for threatened native species and habitats.
"The constant rain and continuing land movement means we're facing some complex and dynamic challenges at some locations, which we're working to resolve with geotechnical experts."
Repairing or rebuilding might not be possible in some places and other options would need to be considered, he said.
"We need to use the cyclone recovery as an opportunity to build in resilience to future climate change and work with others to achieve enduring solutions."
People should avoid closed sites for their own safety, Heinrich said - which included popular the popular Cathedral Cove, Cape Kidnappers/Te Kauwae-a-Māui and Te Henga Walkway.
DOC said biodiversity teams also found about 160 native species and habitats were affected by Cyclone Gabrielle and flooding, and recovery work was underway.