MONTPELIER, Vt. - The Vermont House approved a measure Monday night that would allow doctors to provide lethal medication to terminally ill patients seeking to end their lives.

If Gov. Peter Shumlin - a strong supporter of the bill - signs on, Vermont will join Oregon, Washington and Montana as states allowing physicians to provide deadly doses of medication to dying patients who seek it.

The vote was a reversal of the defeat of similar legislation in the House in 2007 and marked the first time any legislature in the country had seen such a measure all the way to passage.

By a 75-65 roll call vote, the House approved a bill, which largely copies a law passed by Oregon voters in 1997 for three years and then shifts to a system with less government monitoring.

For the first three years, Vermont's law would closely follow the Oregon model, which allows for several safeguards, including requirements that patients state three times - once in writing - that they wish to die. Others include a concurring opinion from a second doctor that a patient has less than six months to live and a finding that the patient is of sound mind.

"It's an important step for terminally ill Vermont patients," Dick Walters, president of Patient Choices-Vermont, said after the vote. "It's a big step forward for the region and for the country as a whole."

The bill's passage likely will be seen as the most historic event of the 2013 legislation session, which is expected to wrap up today.

Vermont would be the first state east of the Mississippi to allow doctors to help patients die by writing a prescription for a lethal dose of medication. Oregon passed the first-in-the-nation law by referendum in 1997; Washington state followed suit in 2006; and a court order in Montana made it legal in that state.

Debate included two packed Statehouse hearings in which supporters and opponents took turns voicing their views on the legislation, sometimes dubbed "death with dignity" by backers and "physician-assisted suicide" by opponents.