NEW YORK -- Soon after Colorado legalized recreational cannabis, Todd Mitchem's son proposed using the plant for a horticulture project at his Montessori school in Denver.

School officials said no way, despite support from dad, a regular weed user and chief executive of a dating app and social network for fellow enthusiasts.

"They didn't want to touch it. They weren't ready to touch it," said Mitchem, who is divorced and shares custody of his kids, ages 11, 9 and 7.

That was early 2013. Now, pot is everywhere in the state, along with three others and the District of Columbia that pushed beyond sanctioned medicinal use to legal consumption just because.