The Lewis Shelter replaces the Lewis Hut and has been built on a high terrace behind the old hut site.
There are panoramic views of the Heaphy valley and the suspension bridge from the shelter, Operations Manager Buller Suvi van Smit says.
"The first track users to stop in after it was finished told rangers who were there that it was absolutely awesome, which was really good feedback to hear.
"It's also a great area for spotting whio, kea, tui, riroriro, tauhou, mātātā, korimako, miromiro, pīwakawaka and weka.
"The shelter will provide emergency accommodation for people travelling between the Heaphy and Mackay huts. Track users can stay there if the river is too high to cross safely. We don't want people to risk crossing the river when it's in flood."
The old Lewis Hut was demolished as it was in poor condition and prone to seasonal flooding and erosion being only 10 metres from the riverbank.
The distance between Mackay and Heaphy Huts can be walked comfortably in a day as long as the river is not in flood.
