Federated Farmers has rebuffed Forest and Bird's suggestion that a drylands conservation area be set up in the South Island's Mackenzie Basin.
Forest and Bird spokesperson Nicola Vallance says it has obtained documents showing the government intends to offer more than 31,000 hectares of Crown pastoral leasehold land in the Mackenzie Basin for sale.
Ms Vallance says large tracts of the scenery have already been turned into intensive green pasture.
She says Forest and Bird wants a plan, in law, to stop further changes to the landscape.
Federated Farmers High Country chairman Graham Reed says if the conservation group wants leasehold land to be incorporated into the conservation reserve, they should buy it themselves.
Mr Reed says the landscape is already modified after 150 years of grazing.
Without livestock, he says, Forest and Bird will not end up with a drylands park, but a place for rabbits, hieracium and wilding conifers.
Meanwhile, Forest and Bird has has welcomed last week's High Court decision in favour of the Environmental Defence Society, which challenged intensive dairy farming in the region.