Little Cash Hyde, a 2-year-old who survived a cancerous brain tumor, is one of that state's 51 medical marijuana card holders under the age of 18.
His father defends the decision, but not everyone thinks it's such a good idea.
"I believe that, you know, Cash is with us for a lot of reasons. He is a patient of medical cannabis, which has, I think, greatly benefited his battle," said Cash's father, Michael Hyde.
"It's a substance that's hurtful for the brain during development. We believe it's harmful for kids and in our opinion, no, we don't think kids should be using marijuana," said Brandee Tyree with Missoula Underage Substance Abuse Prevention.
Lawmakers are currently considering repealing Montana's medical marijuana law.