James Sinks / The Bulletin

SALEM - Two people have been arrested in one of Central Oregon's most notorious vandalism cases - the toppling of a high-voltage Bonneville Power Administration tower six years ago in the High Desert southeast of Bend.

Federal authorities on Thursday announced the arrests as part of a nine-year investigation into so-called ecoterror groups, such as the Earth Liberation Front and Animal Liberation Front, operating in the Pacific Northwest.

A total of six people were arrested, the U.S. Department of Justice said in a release, with suspects taken into custody in Oregon, New York, Virginia and Arizona.

The other four suspects are alleged to have played roles in four separate major arsons dating back to 1998, with three of those blazes each causing at least $1 million in damage.

Arrested Wednesday for the power-line transmission damage were Chelsea Dawn Gerlach, 28, of Eugene, and Stanislas Gregory Meyerhoff, 28, of Charlottesville, Va.

Gerlach pleaded not guilty in federal court Thursday, according to The Associated Press.

Both face potential sentences of 20 years for their alleged roles in the vandalism case.

Meyerhoff is also a suspect in arson fires at Superior Wood Products in Douglas County in 1998 and at Jefferson Poplar Farms in Columbia in 2001. For those alleged arsons, he faces a possible life sentence if convicted.

The investigation is continuing and more arrests are possible, said Kent Robinson, chief of the Oregon criminal division of the U.S. Department of Justice.

The Joint Terrorism Task Force, U.S. Forest Service, Eugene and Portland police departments and the Bureau of Alcohol, Tobacco and Firearms assisted in the inquiry, he said.

”These indictments illustrate that we will pursue these arsons as long as we have to solve them,” he told The Associated Press on Thursday.

In the name of a better environment, loosely organized ecoterror cells have committed acts of vandalism including firebombing of cars in Eugene, burning logging equipment and timber company offices, freeing mink from a Willamette Valley breeder, and hammering spikes into trees to damage chainsaws.

State lawmakers in 2001 boosted criminal penalties for acts that were deemed to be ecoterrorism. However, the suspects named Thursday in the arsons and power line vandalism are facing federal - not state - charges.

”I commend the investigators and, believe me, more arrests are going to follow,” said State Sen. Ted Ferrioli, R-John Day, a timber industry spokesman who led the efforts to boost penalties for ecoterrorism and what he calls ”eco-sabotage” of equipment.

”It always amazes me that Oregonians and others have not been able to make the connection between environmental activism and garden variety terrorism. And these crimes ought to be treated like what they are, which is terrorism.”

While groups like the Animal Liberation Front proudly took credit for the damage their operatives caused, the actual suspects have proved elusive. One ecoterrism suspect, known as Tre Arrow, was arrested in Canada and is awaiting extradition. But most of the incidents have gone unpunished.

The vandalism of the Des-chutes County transmission tower at 8:35 p.m. on Dec. 30, 1999, captured headlines and cable news alerts across the nation as anxiety mounted over the switch to the millennium and the ”Y2K bug.”

The 80-foot tower, 37 miles southeast of Bend, supported a 1 million volt ”inter-tie” line that, at full capacity, can carry enough electricity to light three cities the size of Seattle, said Mike Hansen, a spokesman for the BPA in Portland.

Power was redirected almost instantly after the single-pole tower came down, he said, and it was hoisted back into place within 24 hours.

Still, the incident raised questions about the security of the power grid in the West - and that angst was reinforced for the terrorist attacks of Sept. 11, 2001, Hansen said.

He said the BPA has embarked on efforts to improve the safety of the transmission system, but would not give specifics.