The crossing is closed until further notice.
Mount Tongariro erupted late on Monday, sending rocks and debris flying and ash cloud east across the central North Island.
Businesses which rely on the ski fields on neighbouring Mt Ruapehu did not appear to have been affected. Hoards of skiers and snowboarders were scene making their way up the mountain this morning to enjoy the 20cm of fresh snow which fell overnight.
However, with the Tongariro Alpine Crossing closed until further notice, some businesses are faced with an anxious wait.
"We're now officially unemployed," said Jan Hayter of Tongariro Expeditions, which gives guided tours of the crossing.
"We can only but wait until the track is clear of the ash and the debris and they fix Ketetahi Hut up."
She'd had to cancel the 15 bookings the business had for today, but she was still getting inquiries.
"I had a very interesting talk with a lady this morning trying to get it through to her that it was closed but she was adamant that she would be careful, but I said no."
Ms Hayter said it was not unusual for the business to have to close for a few days when the weather was bad, and she remained positive about the future.
"We've got to have positive thoughts, it's going to be fine. The summer's coming and we're going to have lots of tourists that want to come and see the number one volcanic mountain.
"Wouldn't you want to come and see the mountain that's just erupted?"
Chateau Tongariro manager Tony Abbott said the media would play a large part in determining how the eruption effected business in the area.
"At this stage it's just been a little blip on the volcanic calendar so as long as nothing else happens I think it will be fine."
The Department of Conservation is due to give an update on the situation at 3pm today.
DOC spokesman Bhrent Guy said it was working with GNS Science on a risk assessment of the area today and it was hoped the Tongariro Alpine Crossing could reopen soon.
* For more on the region, see our Tongariro National Park travel section.