County supervisors Tuesday named Ross Herbertson, the executive director of Slide Ranch, to replace Art Mills of Point Reyes Station on the Marin Planning Commission.

Mills, West Marin's only representative on the commission, has resigned to take a ministerial position in the South Bay.

Herbertson, 39, became manager of Slide Ranch Environmental Center in 1985 and was promoted to executive director in 1989. The ranch is located within the Golden Gate National Recreation Area between Stinson Beach and Muir Beach.

Supervisor Gary Giacomini Monday told The Light three people had applied for the commission seat representing the Fourth Supervisorial District. The other two live in East Marin, he said.

A graduate of the University of Virginia in Charlottesville, Herbertson moonlighted as a political consultant to Green Party campaigns in Missouri during 1992 and 1994.

He has served on the Advisory Committee to the Marin Agricultural Literacy Project and the Advisory Committee to Walker Creek Ranch's 1994 Agricultural Education Feasibility Study. He is a contributing editor to Sacred Reflections Quarterly, and is an associate affiliate of Earthshare of California.

As a commissioner, Herbertson said Tuesday, "I intend to speak up for the interests of farmers and the residents of West Marin when issues affecting this area come before the commission.

"As the director of Slide Ranch, it has been an honor to show tens of thousands of Bay Area children and adults something of the agricultural heritage of West Marin and the glory of wild coastline."

How does the new commissioner respond to those who claim the heyday of ranching in West Marin has come and gone? "People say that about our country['s future] as well," Herbertson replied. "What we see in Marin is symptomatic of our national value system."

He acknowledged the preservation of agriculture here requires maintaining a "fragile balance, and I'm going to work toward that." He noted that for ranching to continue, a "critical mass" of ranches must be preserved and warned of attempts to "chip away at that."

The new commissioner spoke enthusiastically about West Marin produce-growers groups and community-based crop cooperatives. While predicting West Marin agricultural will be "somewhat different" in coming years, he noted, "The land form of Marin is inherently suited to grazing. Row cropping will never be a major operation."

One of the major land-use issues scheduled to come before the Planning Commission next year are Nicasio filmmaker George Lucas' expansion plans. The county previously approved a masterplan for subdividing the site, but Herbertson said Lucas' high-tech complex would probably have less environmental impact than a large subdivision.

"I'm willing to look at [Lucas' proposal]," he said but added he may push for more agriculture on the bulk of the property, which is now earmarked for open space.

As for a second major issue facing West Marin - the critical shortage of housing, Herbertson said the only solution may be regional, involving all Bay Area counties. "The single greatest problem of this planet, he added, "is overpopulation."

Herbertson, his wife, and their four children live at Slide Ranch.