Frequently asked questions Is Recreational Marijuana Legal in Montana? As of November 3, 2020, voters in the state of Montana decided to legalize recreational marijuana. Two ballots were introduced and approved. I-190 creates rules for marijuana use, including a 20% tax and the option for individual counties to prohibit dispensaries. CI-118 amended the Montana Constitution to allow the state to set the minimum buying age to 21. However, the state of Montana has yet to set up rules, regulations and begin the process for applications for dispensaries. This means that you cannot buy recreational marijuana legally as of yet. A person over the age of 21 is allowed to possess up to 1 ounce of marijuana, or 8 grams of concentrate (a little over 1/4 oz.), under the law. A person may grow up to 4 mature cannabis plants and 4 seedlings in their own private residence. Any amount of cannabis flower produced that measures over one ounce should be locked away and kept out of plain sight in a private space. If you are renting or using another property, you must have written permission from the owner allowing you to grow cannabis. Consuming cannabis in public spaces is still prohibited, unless it is a designated area where you’re allowed to do so. Employers still have the right to enforce their workplace drug policies, and local governments have the authority to adopt ordinances or regulations on commercial businesses. Understandably, operating a vehicle under the influence of marijuana is prohibited.