The world’s first legal sale of recreational cannabis happened in Denver on Jan. 1, 2014. In fact, it happened twice.

Mason Tvert was managing the onslaught of media that descended on the Mile High City to witness the historic moment set in motion by the successful legalization campaign he’d led. So many camera crews and reporters showed up that morning that Tvert decided to rotate two groups through the dispensary’s sales floor — with each transaction billed as the first time anyone 21 or older could legally buy weed simply by walking into a store, showing ID and paying for it, no doctor’s note necessary.

Cannabis enthusiasts also flocked to downtown Denver that day. Lines outside the new rec stores stretched down city blocks. Buyers exited with purchases in hand, holding them overhead like victory trophies. Rumors even swirled that some stores had sold out, only adding to the fervor. “It was wild,” Tvert recalls.

Monday’s anniversary of the first sales marks a decade since the state inaugurated its new recreational cannabis industry and stepped into the international limelight as a sometimes-reluctant trailblazer. Colorado voters’ passage of Amendment 64 in November 2012, less than 14 months earlier, had launched the state on a journey without a roadmap — forcing regulators to write the blueprint for overseeing the new market and local communities to choose whether they were in or out, and politicians who’d opposed the voter initiative to lead its implementation.