The Transport Agency says the slip blocking State Highway Three through the Manawatu Gorge has been reduced to a sixth of its original size.
It says work on clearing the debris is continuing round the clock and it's still on track to meeting its deadline of opening the road by mid-year.
When all the debris is removed, the agency says the buried road and bridges can be assessed for damage and repaired.
The highway which links Manawatu and Hawke's Bay, has been closed since August.
So far 310,000 cubic metres has been removed from the area. Some 370,000 cubic metres will have been cleared when the job is finished.