“Commercial real estate tracker Xceligent Inc. estimates that marijuana cultivation and manufacturing facilities in the city occupy about 4.5 million square feet — the equivalent of 78 football fields.

This industry has come on so fast that initially I was uneasy — it seemed like a fad,” said Brad Calbert, president of the Colliers International brokerage in Denver. “But what’s making it sustainable is supply, demand and capital. Supply is deficient, demand is excessive, and capital is abundant.”