The critics complained to county planning commissioners that the report shortchanges numerous issues, including traffic, zoning, wildlife, creeks, parking, housing of employees, trails, trees, toxic materials, and noise.

"It's one of the more biased EIRs I have read," said Barbara Salzman, director of the Marin Audubon Society. "It's hard to find an impact that [EIR consultants Berman Nichols] found to be significant."

Added Lucas Valley resident Alan Greenberg, "No draft environmental-impact report is perfect, but this one is really inadequate." The document's "loose and ambiguous terms made it hard to evaluate," he said.

To sweeten the deal, Lucas has purchased two other adjacent ranches - McGuire and Loma - to be left undeveloped. All told, 97 percent of the four ranches - 3,283 acres - would be deeded as permanent open space.

The remaining 108 acres is planned for office buildings and production facilities totaling 640,800 square feet.

The project is a revamped version of an original proposal that was trashed three years ago after it was roundly criticized by neighbors, environmentalists, and county planning commissioners.

Many of Lucas' critics Monday argued vehemently that in order to accommodate the expansion, Big Rock Ranch would have to be rezoned and the countywide plan amended.

Some were miffed that county planners had previously ruled unilaterally that no such changes were necessary.

Jean Fitzgerald, vice president of the Lucas Valley Homeowners Association, said that decision "limited the scope and parameters of the EIR before you today. As a result, this EIR is fatally flawed because it avoids altogether the issue of the project's obvious inconsistency with the Marin countywide plan...

"County planning staff had no legal authority to make the decision without public notice and a public hearing," she said. "Without a public hearing, there is no way for the public to know how much influence the applicant had over this staff decision."

Several neighbors argued that movie companies hardly amount to "light commercial" use, and that production facilities are not office buildings, as described in the permit application.

Lucasfilm attorney Doug Ferguson responded that movie-making has changed drastically in the past five years. These days, he said, the kind of work Lucas does can be accomplished in offices without the need for huge sound stages and studios.

Members of the public can send written comment about the draft environmental-impact report to Tim Haddad at the Marin Community Development Agency, Room 308, Civic Center, San Rafael, 94903-4157. The deadline is Nov. 27.