Residents of Colorado will have the opportunity this November to legalize marijuana possession and allow regulated sales of marijuana in their state.

The Colorado Secretary of State Scott Gessler on Monday certified a ballot initiative for the state's November general election after Denver-based activists gathered more than 170,000 signatures.

If approved by voters, the Regulate Marijuana Like Alcohol Act would allow for the limited possession and cultivation of cannabis by adults age 21 and over. It would also allow the state and local governments to enact regulations on the commercial production and distribution of marijuana, as well giving local governments the option to prohibit marijuana sales altogether.

"This could be a watershed year in the decades-long struggle to end marijuana prohibition in this country," said Art Way, Colorado manager of the Drug Policy Alliance. "Marijuana prohibition is counterproductive to the health and public safety of our communities. It fuels a massive, increasingly brutal underground economy, wastes billions of dollars in scarce law enforcement resources, and makes criminals out of millions of otherwise law-abiding citizens."

Last year, Colorado became the first state in the nation to begin issuing licenses for businesses that sell medical marijuana and marijuana-infused products and also formally asked the Drug Enforcement Agency to reclassify marijuana. Currently, the DEA classifies marijuana as a schedule I drug: the most restrictive classification reserved for dangerous drugs with no real medical value.

Although Colorado has legalized medical marijuana, those who distribute the drug still risk running afoul of federal law. The Obama administration’s Department of Justice has made a practice of not prosecuting medical marijuana patients in states where the drug has been approved, but it still considers distributors to be fair game for arrest.

In January, U.S. Attorney John Walsh sent letters to 23 medical marijuana dispensaries in Colorado, warning them that they faced legal repercussions if they did not close down within 45 days.