DENVER -- Stoked by their surprise victory in Denver, marijuana-legalization advocates are hoping to ride the momentum with statewide ballot initiatives this year in Colorado and Nevada. Colorado activists announced a drive two weeks ago aimed at bringing a clone of Denver's Initiative 100 before voters statewide in November. Initiative 100 allows adults in the city to possess small amounts of marijuana.

And activists in Nevada, who have secured a place for a legalization measure on the state ballot in November, are taking heart in the success of Initiative 100, which captured 54 percent of the vote in the Nov. 1 election.

"What Denver shows is that this is a mainstream issue," said Neal Levine, campaign manager of Citizens to Regulate and Control Marijuana in Las Vegas.

If the measures pass, Colorado and Nevada would become the first states to win voter approval for marijuana legalization.

Alaska allows adults to possess up to 4 ounces of marijuana in their homes, thanks to court decisions upholding privacy rights, but voters defeated a 2004 initiative that would have abolished all penalties for possession and regulated marijuana sales.

Denver political analyst Eric Sondermann warned that interpreting the Denver vote as a mandate for statewide legalization would be "a big mistake." He noted that the Denver measure never took effect because authorities have since prosecuted violators under the state law. "The Denver vote was seen mainly as a symbolic vote with no statewide impact," Mr. Sondermann said. "This will be seen as amending state law."

Voters of these Republican-leaning states are known for their independent, anti-big-government orneriness, advocates say.

"There's a libertarian streak in Colorado and a respect for people's individual rights throughout the West, so there's no reason people shouldn't vote for this," said Mason Tvert, campaign director of Safer Alternative for Enjoyable Recreation, the Denver-based group behind Initiative 100 and the statewide campaign.

Both state proposals would legalize possession of up to 1 ounce of marijuana for adults older than 21, but that's where the similarities end. The Colorado proposal, which goes before the Legislative Council on Wednesday for review, says nothing about sales, production or taxation. However, the Nevada initiative provides a detailed regulation system in which marijuana would be sold only by state-licensed vendors and located no closer than 500 feet from churches and schools.

Sales would be prohibited in gambling establishments, and penalties for selling marijuana to minors or driving under the influence would be doubled. The measure also earmarks half the revenues from taxing and licensing for alcohol- and drug-treatment education, with the other half going to the state general fund.

"The approach we've taken in Nevada is that what we need is a system of regulation, not the Wild West, which is what we have now under prohibition," said Bruce Mirken, spokesman for the Marijuana Policy Project in Washington, which is directing the Nevada campaign. "The message is to treat it the same as we treat alcohol."

Eleven states, including Colorado and Nevada, permit the use of marijuana for medical reasons, and several cities, including Seattle and Oakland, Calif., make possession the lowest law-enforcement priority.