Denver voters could authorize over-21 marijuana clubs.
A ballot measure submitted Friday would ask voters whether the city should allow marijuana clubs, as long as the clubs don't sell the pot or even sell alcohol.
Denver already has some private pot clubs, but law enforcement raids have kept the industry somewhat underground.
Colorado law bans public use of marijuana and on-site pot consumption at dispensaries. But activists say that the law should permit clubs as long as they don't allow minors or sell the marijuana. Pot clubs are common in Colorado cities outside Denver.
A similar ballot measure was proposed last year by activists would have allowed bars to allow marijuana consumption. That proposal was later withdrawn.