A woman pleaded guilty Wednesday to conspiracy and arson in the 2001 firebombing of the University of Washington's horticulture center, one of the Northwest's most notorious acts of ecoterrorism.

Under Jennifer Kolar's plea agreement, federal prosecutors will ask U.S. District Judge Franklin Burgess to sentence her to five to seven years.

Kolar, 33, did not comment after entering the plea. Her sentencing is scheduled for Jan. 5.

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The fire on May 21, 2001, severely damaged the building, which was rebuilt at a cost of about $7 million. The center had done work on fast-growing hybrid poplars in hopes of limiting the amount of natural forests that timber companies log.

The Earth Liberation Front, a shadowy collection of environmental activists, claimed responsibility five days after the fire and issued a statement saying the poplars pose "an ecological nightmare" for the diversity of native forests.

Kolar also pleaded guilty Wednesday to an attempted arson charge for a failed 1998 firebombing that damaged a Colorado gun club that organized a multistate turkey shoot.

Another defendant in the UW case, Lacey Phillabaum, 31, of Spokane, was expected to plead guilty in court later Wednesday.

At least three others were involved in the UW firebombing, court documents allege.

Briana Waters of Berkeley, Calif., has pleaded not guilty and is scheduled for trial in May. William Rodgers of Prescott, Ariz., committed suicide in jail after being charged with other acts of ecoterrorism.

A fifth suspect, Justin Solondz, formerly of Jefferson County, Wash., remains at large.