University of Colorado grad student Justin Keller and his girlfriend, Angela Nilles, have hunted down the Rock so many times now that we're dubbing them the Boulder Rocks quadruple threat (or, we will next year, when Keller is eligible to compete again).

Keller, who is working on a Ph.D. in math, and Nilles, a teacher, have put their heads together to solve the clues and find the rock four times now. This week's clues were pretty tough compared to others, he said. Late Thursday night, the two tracked down the Week 2 rock by flashlight after putting together the first four clues.

“Angela figured out the Mount Rushmore connection, which brought us to Dakota Ridge,” he said. “Then I made the win-gate clue make sense. So we're like, OK, it has to be on Fifth Ave., between Wingate and Dakota.”

(Tuesday's clue mentioned stones and faces -- Mount Rushmore is in South Dakota -- and Wednesday's clue read: “If you want to win $500 today, better be first out of the gates.”)

Thursday night was Keller's third trip up to Dakota Ridge to search for the Rock. He usually rides his bike around town to look for the Rock while Nilles is at work during the day, but they borrowed a friend's car for this nighttime escapade. (Keller plans to fill the friend's gas tank to say thank you.)

He'd been searching near the park. “But it wasn't in the park, it was under a bush on a fence on the border of some open space.


It was right at the end of Wingate Ave.”

Keller said searching for the rock is good exercise, and he and Nilles both like the problem solving in the hunt. “I do a lot of the leg work,” he said. “She's more the brains of the operation.”

“We collude to think about the clues and try to figure them out, but I have a lot of free time during the day -- I'm just doing math research, so there's no set schedule, I can just go out and bike during the day.”

He added that he was heading to his research fellowship immediately following the interview, “in case my advisor is reading this.”

How will Keller and Nilles spend the $500?

“We're going to a friend's wedding in a couple of months, so we'll probably just recoup the tickets. We never do anything exciting with the rock money.”