"Both domestic visitor and Australian visitor spending is the strongest it has been for more than 10 years," Cameron said.
"The success of last year's Australian winter marketing campaigns saw Ruapehu take part in two Tourism NZ-led campaigns targeting the Australian skier market for the 2018 season."
Australian visitor spending was up 39 per cent on July 2017 and domestic visitor spending increased by 35 per cent.
The spending increases represent an extra $8.25 million for the region's economy for July.
The total increase in spending for the year ended July 2018 was $21m (11 per cent), up from $191m to $212m.
"A key aspect to Visit Ruapehu's successful strategy has been to work in partnership with tourism operators, government agencies and regional and national partners to promote the Ruapehu region," Cameron said.
Ruapehu Alpine Lifts (RAL) sales and marketing general manager Michelle Caldwell said there was huge year-on-year growth in skier days in June and July.