A federal judge has rejected a lawsuit aimed at halting a hotly protested Highway 101 bypass around Willits.

The environmental groups that filed the lawsuit against Caltrans last year were disappointed but not surprised by the ruling, which was signed Thursday by U.S. District Court Judge Jeffrey White.

White had denied an injunction to stop work on the 5.9-mile, $210 million bypass before it began 10 months ago, then delayed issuing a ruling until work was well underway.

"Once large amounts of earth start getting moved, it's really pretty much impossible to stop a project," said Gary Hughes, executive director of the Environmental Protection Information Center. But bypass critics are not giving up hope of at least altering the project to reduce its effects on wetlands in the Little Lake Valley adjacent to Willits, he said. Other plaintiffs in the lawsuit included the Willits Environmental Center, the Arizona-based Center for Biological Diversity and the Mendocino County chapter of the Sierra Club.

Caltrans officials also had anticipated the ruling and were relieved it was finally issued.

"We're very happy this is no longer hanging over the project," said spokesman Phil Frisbie.

The bypass, conceived more than 50 years ago, became increasingly controversial in recent years as plans were drawn and discussed at public hearings.

Protests erupted as Caltrans began work early this year. Dozens of arrests were made as demonstrators tried to block construction. Some chained themselves to equipment while others stationed themselves in trees in construction zones.

Bypass opponents say it's unnecessary and that it will destroy wetlands, harm fish and irrevocably change the rural nature of the Little Lake Valley.

Proponents say the bypass will reduce vehicle exhaust, improve safety and alleviate traffic jams through Willits, where Highway 101 is the main thoroughfare. The bypass will eliminate the last traffic signals on Highway 101 between San Francisco and Eureka.

The lawsuit contended that Caltrans' environmental studies and its rationale for a four-lane bypass were flawed.

It sought to force Caltrans to conduct additional studies and to consider a two-lane bypass alternative that would have fewer effects on wetlands.

The bypass initially will be just two lanes, but Caltrans plans to expand it to four when it can secure further funding. Meanwhile, it is constructing the base of the bypass to accommodate four lanes.

The first phase is expected to be completed in late 2016.

(You can reach Staff Writer Glenda Anderson at 462-6473 or glenda.anderson@pressdemocrat.com.)