With legal recreational marijuana sales to begin Saturday in Montana knowing what you can possess is important. A person is allowed up to 1 ounce of marijuana. Possession of more than 1 but less than 2 ounces could mean a possible $500 fine for a third or subsequent offense. Possession of any greater amount remains a felony as it was before the 2020 election. Something not well known is consuming marijuana in a public space could trigger a $50 fine.