Spring 2009's Ice-out for the Tanana River Has Occurred!
Date and Time: May 1 at 8:41 pm

About This Site
The Tanana River (65.5N, 149.0W) is at the Nenana, Alaska Ice-Out Observation Post. Since 1917, spring's official arrival in this Interior Alaskan town is defined as the moment the Tanana River is ice free. This event is measured down to the second with a special tripod erected on the ice with a trigger to an official clock.

• See photos and follow the action on the official Nenana Ice Classic Web site. (Click on "Current Ice Conditions.")

To help in your prediction, see the Tanana's ice-out dates since 1990:

Year	Month	Time
1990	April 24	5:19 p.m.
1991	May 1	12:04 a.m.
1992	May 14	6:26 a.m.
1993	April 23	1:01 p.m.
1994	April 29	11:01 p.m.
1995	April 26	1:22 p.m.
1996	May 5	12:32 p.m.
1997	April 30	10:28 a.m.
1998	April 20	4:54 p.m
1999	April 29	9:47 p.m.
2000	May 1	10:47 a.m.
2001	May 8	1:00 p.m.
2002	May 7	9:27 p.m.
2003	April 29	6:22 p.m.
2004	April 24	2:16 p.m.
2005	April 28	12:01 p.m.
2006	May 2	5:29 p.m.
2007	April 27	3:47 p.m.
2008	May 6	10:53 p.m.
2009	May 1	8:41 p.m.

The Tripod Story
Each year a black-and-white tripod is "planted" into the ice of the Tanana River. A wire attached to a rope runs from the top of the tripod to a contraption in a watchman's tower on shore. Watchmen make sure nobody messes with the tripod. Anticipation builds as the weather warms. The ice under the tripod gets slushy, and then the water begins to flow. When water flows on the bank near the watchtower, the time is near. One day or night, the rocks jerk to the top of the tower as the tripod begins its journey, jerking along as the breaking ice chunks begin to move! One watchman described it as just like an earthquake, with rumbling and shaking when the ice starts to go.

When the ice breaks and the tripod begins to move, the rope raises a 50-gallon drum of rocks to the top of the tower. The action trips another line that releases a guillotine that cuts the main rope to the tripod. The cutting of that rope trips two other ropes. One rope stops a clock and the other sets off a loud siren. That's when the whole town finds out the winner of Alaska's oldest lottery, the Nenana Ice Classic. It's a big deal because the Ice Classic has handed out millions of dollars in prize money since 1917--for guessing the exact time the ice breaks up. What's YOUR guess for this year?