Buddy Schmalz and Dave Thomas don't know the answers for sure, but they do know that the plants make a good beer, which Schmalz has been brewing at his Dostal Alley Brewpub (and casino!) since it opened in 1997.
"Every year, I see homebrewers come up here and pick bagfuls," he says, adding that the plants aren't hard to find. "I'm surprised there aren't more."
The beer, Jacob Mack, is named for the man who founded the Mack Brewery, one of six Central City breweries that helped settle miners' neves more than a hundred years ago. And while the Mack Brewery lies in ruins outside of town, the hops flourish.
Can the same be said for Central City itself? You can read about the town and its upscale, down-the-hill neighbor, Black Hawk, in Westword's current cover story. For photos of Central City's beer history, look below.