Mr Kean said it was "great" that the council wanted to strengthen protections for Manobalai Nature Reserve by expanding the reserve and making it a national park, under the environment minister's plan to create another 200,000 hectares of national park land in the next two years.

Manobalai Nature Reserve, 20 kilometres west of Muswellbrook, is an important 3758-hectare vegetation corridor between Goulburn River and Wollemi national parks, is a place of Aboriginal spiritual significance and home to 28 species of threatened native plants and animals, Mr Kean said.

He met with council representatives, including mayor Martin Rush, last week and unanimously resolved to make the case for its expansion and inclusion in the ambitious national park plan.

A council spokesperson said a new national park would embellish the Upper Hunter, and particularly the Denman area, as a tourist destination.

The council believed its proposal could be one of the first, if not the first, formal request to Mr Kean under his national park plan that was announced in mid-August.

"I'm writing to all members of parliament and councils asking them if there are any areas they would like to see reserved because the people of NSW know what they would like to see protected in their own backyards," Mr Kean said.

"Expanding the footprint of our National Parks is not just about quantity but it's about quality and I look forward to hearing from communities across NSW."

Manobalai Nature Reserve was gazetted in 1967, with additions in 1969 and 1974.

The National Parks and Wildlife Service said the reserve represented a distinct transition between bioregions because of its position at the junction of the central western slopes, central tablelands, central coast and north coast botanical divisions.

"The unique location of the reserve contributes to the diverse vegetation patterns and an overlap of species typical of both coastal and western slopes habitats," the NPWS said.

Mr Kean's ambitious plan to add 200,000 hectares of national park land in two years represents a dramatic increase for an environment minister under a NSW Coalition government.

The Nature Conservation Council said the Berejiklian government had added just 4200 hectares a year to national parks in the past two years. Coalition governments over the past eight years have averaged 9450 hectares a year.

The Conservation Council said Liberal governments in the past led by Robert Askin, Tom Lewis and Eric Willis had increased the national parks estate at the rate of about 106,000 hectares a year in the 1960s and 1970s.

Labor governments added 1.856 million hectares during the Wran-Unsworth years from 1976 to 1988 and 3.06 million hectares between 1995 and 2011 under premiers from Bob Carr to Kristina Keneally.