The Department of Conservation says the decision to re-open the Tongariro Crossing on Labour Weekend in October was the right one.
The crossing was closed on Wednesday following the eruption from Te Maari Crater on Mt Tongariro about 1.30pm which pushed a plume of ash and gas about 2km into the air.
In August the crater erupted for the first time in more than a century, ejecting rocks that fell up to 1km away and forcing the closure of the popular Tongariro Crossing track for trampers.
It was re-opened at Labour Weekend and there were a number of trampers on the mountain, including up to 90 school students, who had to hurry off the mountain when it erupted on Wednesday.
But DOC Ruapehu area manager Jonathan Maxwell said he didn't regret the crossing being reopened.
"We'd had a fairly stable time after the initial eruption," he told Radio New Zealand.
"We have a rahui (restriction) in place a kilometre around that Te Maari crater. That proved to be a good call and the right distance so no one was anywhere near it."
Mr Maxwell said the crossing would be closed for at least three days, after which a new assessment would be made.
He said anyone wanting to view the mountain on Thursday would be best to do so from State Highway 46, which was safe and provided a good view.
Mr Maxwell said the crossing was important for businesses in the area, but that would play a small part in the decision on when to re-open it.
"That is a factor but it's not the paramount factor. The paramount factor is the safety and obviously we do not compromise that."