A 20m section of the Queenstown Trail fell away over the weekend after high river levels scoured into the bank.
The slump on the Kawarau River section of the trail, which borders Remarkables Park, was first noticed on Friday.
Queenstown’s council is creating a detour around the slump, which should be in place by this afternoon (Monday).
Community services general manager Paul Wilson says: “Over the weekend it became apparent the area was slumping further and we have had to take action to close the trail at that point for safety reasons.
“It will be sometime before we can reinstate the original trail, possibly two-three months. The detour will ensure the trail can stay open.”