"We've spent a year working with the council over the Craggy Track, we've been trying to sort things out in a reasonable way, and we've actually been making a lot of progress in educating people I think.
"And then this happens and it just rips the wound open again."
Ovation has apologised and removed the ad, saying it never intended to offend, 1 News reported.
The ad might have been pulled by Ovation now but damage had already been done, as it had been printed en masse in some publications, Mohi said.
Ngāti Kahungunu spokesman JB Heperi-Smith told 1 News the ad makes him feel like "we've just taken a hundred steps back again."
Ovation said it would take some time to eliminate the ad from promotional material that had already been distributed.