The measure would create state-regulated, non-profit medical marijuana dispensaries, similar to California.
Supporters say Oregon's measure has an important difference: the state will determine regulations, not local governments.
"By having the model built in advance, we're able to keep it in control at all times," said Oregon medical marijuana patient Jim Greig, also a member of Voter Power
The goal is to avoid a situation similar to Los Angeles.
Earlier this year, the Los Angeles city council approved an ordinance that was limit the number of dispensaries to 70. The ordinance was a response to the hundreds of dispensaries that opened their doors before the city began regulating.
In California, regulation is left up to local governments so the number of dispensaries and rules governing them varies widely.
For example, there are just four licensed cannabis clubs in Oakland. The city council is mulling new legislation that would increase to eight.
Measure 74 would required dispensaries and growers to register with the state, unlike California's law. It also directs the Oregon Health Authority to set rules about dispensary locations, inspections and licensing.
A spokeswoman for the state Public Health department said, because of laws preventing state agencies from campaigning, they have not discussed how Measure 74 would be enforced or implemented. That research begins only after voters pass measures.
Dispensaries are already being opened in the state, said Greig, adding this is Oregon's chance to do things right.
"People need their medicine. It's going to happen," said Greig. "At least with Measure 74, it's going to have some regulation, keep the guidelines."
But not everyone agrees.
Detective Ray Myers of Grants Pass Department of Public Safety, who is a member of the Rogue Drug Enforcement Team in Southern Oregon, said Measure 74's regulations will not make a difference because they don't address abuse of the program.
"It's difficult right now to investigate and prosecute people we believe are involved in the abuses of the Oregon Medical Marijuana program," he said. "This adds two more levels to that."
Myers, who discussed the ballot measure on his vacation time, said officers need search warrants to inspect medical marijuana grows. They are difficult to obtain unless a user gives testimony, so many grows police suspect are illegal because of size, go uninspected.
"There's nothing in there [Measure 74] that says mandatory, surprise inspections," he said.