Today I put a time countdown clicker for the Nanana River Ice Classic on this blog. Every year the residents of Alaska buy a ticket making a guess at what day and time the Nenana River breaks up and flows down river.
Tripod set up on the ice waiting for breakup
Alaskans wager thousands of dollars yearly on the day and time of the break up of the Tanana River. The prize is worth it - over $300,000 this year, and that is only the main contest - minute pools abound, too.
Large grooves are cut into the frozen Tanana River ice about 300 feet from shore. Volunteers lends their muscles to pull on ropes to stand a wooden tripod upright. Holes are drilled in the ice, allowing water to seep upwards, filling in the grooves to freeze the tripod in place.
A watchtower erected next to the tripod holds the official clock of the most recent breakup, and provides a "photo opportunity" for visitors while they wait for the ice to move.
Once the ice has thawed to the point where walking on it is no longer safe, a wire is attached from the watchtower on shore to the top of the tripod, and rigged up to a clock mechanism so that the clock will be stopped when the tripod moves 100 feet. Watchmen monitor from the time the clock is activated until the ice has gone out. A siren will alert the townspeople to the tripod's first movement.
When the tripod trips the clock, spring has officially arrived, and Interior Alaska's rivers are once more navigable. And someone is a lot richer.
Closeup of a tripod set up on dry land