MISSOULA, Mont. - People marching against Monsanto carried signs Saturday afternoon from the courthouse to Caras Park.
Activists hope to raise awareness of the use of GMO's in the food system and ask for clear labels on food.
They say GMO's are risky because there has been little research done to assess possible dangers to the environment and people's health.
The organizer says they want Missoula to know what GMO's are and says there is a need to support local farmers.
"We need to support our local farmers. Our bees are disappearing because of these pesticides. We need to support locally and stop this. It's madness, it's crazy! It sounds insane, but it's really happening," said Monsanto March Organizer Suzanne Demarinis.
Monsanto is one of the largest companies developing GMO's. The company's website claims genetically modified seeds have been tested more than any other crops in the history of agriculture - with no evidence of harm to humans or animals.