$2,500 Emerald City Search is back

Alert: The medallion has been found. The contest is over.

The Seattle treasure hunt is back. Here's a hint about this year's theme: Mark Twain and Calaveras County.

Here's another hint: It's what a princess kisses to find her prince.

Sorry. In the third annual Emerald City Search, the rest of the clues aren't that easy.

Remember the contest? Ten clues spread over 10 days. First contestant to find a medallion hidden somewhere in the city wins $2,500 in cash and prizes.

Tech heads, librarians and retirees have wised up since this treasure hunt started two years ago. Many team up. They coordinate by cellphones.

We expect Twitter will be big this time.

This year's theme — please tell us you've figured it out — is The Year of the Frog, and it promotes a Woodland Park Zoo campaign to raise awareness about the high death rate of amphibians in the Northwest and around the world.

"The increasing pressures of human population growth, climate change, pollution and invasive species on our natural world makes conservation biology a critical focus," said Ray Huey, chairman of the University of Washington's Biology Department.

The clues were written by the faculty of the UW's College of Arts & Sciences, which is organizing this contest with the Hillel Foundation and UW Alumni Association.

Here's some background to get you started:

Frogs are in decline around the world. Woodland Park Zoo estimates that up to 165 amphibian species may already be extinct, victims of a parasitic fungus, exotic predators and other environmental threats.

Take the spotted frog, listed as an endangered species in Washington. Plants and developments invade their habitats.

In recent weeks, behind closed doors, a team of four experts has brainstormed to come up with the riddles that make up this year's clues: Marc Hayes, curator for herpetology at the Burke Museum; Janneke Hille Ris Lambers, assistant professor of biology; Josh Tewksbury, associate professor of biology; and Robin Wright, curator of Native American art at the Burke Museum. The riddles are designed to be hair-pullingly difficult the first few days but get easier as the hunt goes along.

We know. We know. That's what organizers said two years ago during the treasure hunt's inauguration.

The theme then: the Dead Sea Scrolls. The eat-crow moment: Oct. 21, 2006. That's when a Lake City couple, who either were extremely lucky or the type who could solve the Rubik's Cube during commercial breaks, found the medallion on a concrete rail post on Alaskan Way with just three clues.

But we digress. Organizers are convinced the puzzle gods will not be on your side this year — at least not early in the hunt.

Organizers recruited "puzzle masters" Jeff McCord and Stephen Shippert, who have backgrounds in designing trivia, board and computer games. The duo did a test run of the treasure hunt and found the treasure in five clues. The riddles have since been made harder.

With their guidance, organizers are convinced you won't find the medallion during the first week of the hunt.

Sounds like a dare to us.

Tan Vinh: 206-515-5656

or tvinh@seattletimes.com