They say that brings their total signatures submitted to 145,000. That's far more than needed to qualify the measure for the November ballot.
Efforts to legalize recreational pot in Oregon have been boosted by the collapse of two other initiatives that were competing with one that has attracted wealthy donors.
If Oregonians approve the remaining measure in November, the state would join Colorado and neighboring Washington state in legalizing recreational pot.
The measure would legalize pot for adults over 21, while giving the Oregon Liquor Control Commission authority to regulate and tax marijuana.
A measure in 2012 failed, but supporters this time say they're confident they'll have the votes.