FOUNTAIN, Colo. — As their children cooed from wheelchairs and rocked softly in their arms, the marijuana migrants of Colorado clasped hands, bowed their heads and said a prayer of cautious thanks.

They thanked God for the dinner of roast turkey and mashed potatoes, for their children and for the marijuana-based serum that has drawn 100 families to Colorado on a desperate pilgrimage to quell the squalls of seizures inside their children’s heads. They have come from Florida and Virginia, South Carolina and New York, lining up to treat their children with a promising but largely untested oil that is considered legal medicine in this cannabis-friendly state.

“Thank you for bringing us together,” said Aaron Lightle, whose wife and 9-year-old daughter, Madeleine, moved here after the girl’s neurologists suggested removing part of her brain to stop her relentless seizures. “In crazy ways, maybe. But hey, we’re here.”

Amen, they said.

Their migration is one of myriad ways that a once-illicit drug is reshaping life here in Colorado, which now stands at the forefront of the national debate over legalizing drugs. While these families are seeking treatment through a medical marijuana system that has existed for years, they are arriving at a time when the drug is becoming a mainstream part of public life, made legal for recreational use in a historic vote last year.