When spring finally arrives in Nenana, Alaska, it’s cause for celebration -- and a cash payout. Every February, the town’s fewer than 400 residents start watching the ice melt -- literally.

A tripod is set up on the frozen Nenana River and connected with a cord to a clock. Residents place bets on the exact date and time the ice will give way, which is marked when the ice melts and forces the tripod to move and the clock to stop.

Now in its 101st year, the Nenana Ice Classic has grown so popular that Alaskans throughout the state buy tickets. In some recent years, the prize money has ballooned to more than $300,000.

Last year, there were 42 winning tickets when the ice finally gave way at noon on May 1. When the ice melts this year is anybody’s guess.