HELENA - Early season ice skating can be high risk, high reward because the newly formed ice is usually thin but smooth.
As a general rule, ice is safe to walk on when there is four inches or more of clear ice.
Clear blue or black ice is the strongest. This ice is formed from the lake water freezing.
White, opaque ice is weaker and is often formed from snow falling on the ice surface, partially melting, and then freezing.
Gray ice is even weaker and is formed as it starts to break down.
Follow the old saying, "thick and blue, tried and true, white and crispy, way too risky."
Besides the color of the ice, look for snow cover as ice covered in snow will be weaker than exposed ice as snow insulates.
Ice along the shoreline is often weaker. Larger bodies of water can have hidden currents that might prevent thick ice from forming.
Where rivers enter or exit the lake can have weaker ice. and objects like plants, rocks, or downed trees will absorb sunlight and heat, possibly weakening the ice.
So ice thickness recommendations are if it's 2" or less to stay off. Four inches of ice is safe for ice skating, ice fishing, or other activities on foot.
Five inches of ice is safe for a snowmobile or ATV and 8-12" can support a car or small pickup.
Better make sure it's that thick or you'll have to wait until the ice melts in the spring to fish out your vehicle.