If you live in Colorado, Washington or Oregon, your state may soon be the first in the nation to allow possession of marijuana—in limited quantities—for recreational use. It all depends on what happens Nov. 6.

Pot is no stranger to the ballot in Colorado, where smokers consume more than two million ounces of marijuana each year and the state spends more than $40 million annually enforcing its prohibition. A ballot initiative to legalize marijuana failed 59% to 41% in 2006, six years after a referendum approved medical marijuana for use in the state. This year, cannabis advocates filed eight different petitions to legalize marijuana for recreational use under the state’s constitution, a proposal whose fate voters will decide on Election Day.

Supporters argue that a regulated marijuana market would yield an economic boon. An August report from the Colorado Center on Law and Policy found that the amendment could generate $60 million from criminal cost savings and new tax revenue. Proponents plan that the first $40 million generated would go toward the state’s school construction fund, which would help create nearly 400 new jobs. “Regulating marijuana like alcohol will take sales out of the hands of cartels and gangs and put them in the hands of legitimate Colorado businesses,” says Mason Tvert, co-chairman of the Campaign to Regulate Marijuana Like Alcohol, which has out-fundraised its opponents nearly four to one. “The question is whether we would prefer it be strictly controlled and sold by licensed businesses in a regulated market, or whether we want to continue with the current system in which it is strictly uncontrolled and sold by criminals in the underground market.”

Coloradoans favor marijuana legalization 48% to 43%, according to a recent Denver Post poll, down slightly from a 51% to 40% lead last month. Much of the new resistance comes from women, who flipped from supporting the measure 49% to 39%, to opposing it 48% to 40%. “Amending Colorado’s Constitution to make our state the marijuana capital of the US is wrong for our kids and our economy,” says Laura Chapin, communications director for Smart Colorado, one of the main groups challenging the proposed amendment.

Washington also has a marijuana legalization initiative on the ballot—and supporters of the measure led in a recent poll 54% to 38%. The Washington initiative, like Colorado’s, would treat marijuana like alcohol at new state-licensed marijuana stores; users would have to be over 21 and purchases would be limited to one ounce. Oregon is attempting to pass a similar measure, but polling indicates it is less likely to succeed: opposition leads support 43% to 36%.

If any of the recreational marijuana measures pass, federal authorities have indicated they would likely initiate a challenge. US Deputy Attorney General James Cole told 60 Minutes that the Justice Department would continue to watch for “dangers to the community from the sale of marijuana” and if so, “we’re going to go after those dangers.” Federal prosecutors cracked down on medical marijuana in California last year, closing hundreds of dispensaries.

Medical marijuana is making three ballot appearances this year, in Massachusetts, Arkansas and Montana. (Montana voters approved a medical marijuana law in 2004, and this new measure would repeal it to create a new marijuana program.) California—the first state to make medical marijuana legal after voters passed Proposition 215 in 1996—attempted to more broadly legalize pot on the 2010 ballot, but the vote fell short. Medical marijuana use is currently legal in seventeen states and the District of Columbia.