Environmental groups sued the U.S. Forest Service in San Francisco federal court Thursday in a bid to throw out new management plans for the four Southern California national forests, saying they don't adequately protect the open-space islands from the pressures of an ever-expanding urban region.

Those forests include the Cleveland, which covers 460,000 acres in San Diego, Riverside and Orange counties, and the 665,000-acre San Bernardino forest in Riverside and San Bernardino counties.

The Cleveland takes in Palomar Mountain, the pine-covered mountains around Julian and the oak- and chaparral-carpeted hills west of Lake Elsinore. The San Bernardino is home to the alpine forests around Idyllwild and Southern California's highest peak, the 11,502-foot San Gorgonio Mountain.

The groups alleged that the plans, several years in the making and adopted in 2005, leave some of the region's best preserved natural lands vulnerable to damage from new roads, motorcycles, power lines and grazing, and asked that the Forest Service be ordered to come up with new blueprints for long-term forest management.

It is time to start over, said David Hogan, conservation manager for the Center for Biological Diversity in San Diego, one of seven groups to join the lawsuit.

"The plans were written by a presidential administration that has been extraordinarily hostile to environmental protection," Hogan said in a telephone interview.

"What we really have right now is a choice between managing Southern California national forest lands for the benefit of recreation and nature, or, as the Forest Service has chosen, for development and exploitation," he said. "These national forests are surrounded by populations of millions of people. They have become last refuges for wildlife and nature, and for people who want to escape the urban grind."

John Heil, a spokesman for the Forest Service's California office in Vallejo, declined comment, saying the federal agency has a policy of not talking about lawsuits.

The Center for Biological Diversity was joined in the suit by the Sierra Club, Defenders of Wildlife, the California Wilderness Coalition, Wilderness Society, California Native Plant Society and Los Padres ForestWatch.

The lawsuit follows two other suits about the forest plans filed in the same federal district court earlier in the year. Those challenged pieces of the plans.

In March, the state filed suit, alleging that the plans wrongly opened some roadless areas to building roads. During the same month, the Center for Biological Diversity alleged that the plans fail to properly protect imperiled species that live in the forests.

This latest action is the first to challenge the plans in their entirety, Hogan said.

Administrators for Cleveland plan to add a dozen miles of new roads to accommodate the growing demands of riders of motorcycles and all-terrain vehicles in the backcountry. Utilities have proposed building power lines across portions of the forest in North San Diego County near Ramona and in Southwest Riverside County near Lake Elsinore.

Contact staff writer Dave Downey at (760) 745-6611, Ext. 2623, or ddowney@nctimes.com.