The fake rocks have words painted on them in yellow; the real Rock bears an engraving.
R.J. Fogal, owner of Creative Management Innovations, was out looking for the Rock -- which comes with $500 and free tickets to Riot Fest Denver -- Wednesday evening when he came upon a doppelganger off the Goose Creek bike path near 28th Street.
"It says 'Colorado' on the top in yellow letters," he said. "But when you flip it over, 'loser.com.'"
Firefox could not find the server for coloradoloser.com, and thus no domain owner was available for comment.
Joseph Placek and his wife, Catherine, were out searching for the Rock late Wednesday afternoon when they found a painted rock.
"Mine says, ‘hiya xoxo winner,'" Placek said with a laugh. "I'm putting it on the dashboard of my car as a souvenir."
Placek and Fogal both laughed over the fake rocks and said they wouldn't be deterred from continuing the search for the real deal.
"We'll keep trying," Placek said. "We're having fun no matter what.
Chris Donahue was on his way to the dentist, and since the first clue this week was about dentists, he decided to look for the Rock before his appointment. He quickly found a rock with a painted yellow star atop a utility box near the Goose Creek path.
"It didn't look anything like the pictures of past winners," he said. "I wasn't sure. When I discovered this one, I thought, um, OK, that's the way they present it."
Donahue was bummed to have missed out on the prize but shrugged off the fake. He's always participated in the hunt, he said, and he wasn't going to stop now.
"There's lots of creative, artistic people around Boulder," he said, adding: "Hopefully I can go back out and find it."
As of Wednesday evening, the real Rock had not been found.