Survive a Fall Through Thin Ice

Survey ice-covered water carefully to determine the safest place to cross. Photo © Traci J. Macnamara.

In the springtime, thick ice that has formed over bodies of water during the winter begins to become unstable with warmer temperatures. You may have walked confidently over an ice-covered river, creek, or stream in the winter months, but once the ice begins to melt, you’ll have to think carefully about where you can make the safest crossing--or whether or not it’s safe to cross at all.

Since falling through thin ice will put you in danger of hypothermia and other cold-weather injuries, avoid thin ice by taking in clues from your surroundings.

Survey the ice conditions carefully before making a crossing, and proceed with the skills and tools that will help you make it across safely. Finally, if you do fall through thin ice, know how to get out safely and how to treat potential injuries. Follow this advice to help you each step of the way:

Avoid Falling Through Ice

Take in clues from your surroundings to determine whether or not you might be in danger of falling through thin ice. If you’re carrying a map, look carefully for blue water markings so that you know where you might encounter ice-covered bodies of water. Snow may cover the ice on top of these bodies of water in the winter and early spring, so you may not even see any ice. Use other senses and terrain knowledge to help you determine when ice is near.

Look out for smooth, snow-covered depressions in the landscape; avoid walking over them, as they could be frozen lakes or ponds.

And listen carefully for gurgling or cracking sounds, especially in the spring, to determine where water may be flowing underneath layers of snow and ice. Look for deep, clean fissures in the snow, as these cracks can alert you to water flowing beneath.

Look out for areas where water likely flows, such as gullies or ravines; and look for vegetation patterns, such as willow patches, to alert you to a water source.

In these areas, listen carefully as you approach, and then determine the safest place to cross.

How to Cross Thin Ice

First of all, approach an ice crossing with a great deal of caution since any crossing has its potential hazards--and those hazards are even greater as ice thins in the spring.

  • Look for an area in which the ice is clean, clear, and new; old ice is less stable than new ice.
  • Check the thickness of the ice, looking for an area with a minimum of four inches of thickness. Avoid walking on ice that’s less than two inches thick. Also note that ice may not be of uniform thickness, so check thickness in several areas as you cross.
  • Unbuckle your backpack before crossing so that you can get it off your back quickly in case you fall through the ice.
  • Carry trekking poles or a long pole-like branch horizontally in front of you while you cross to help you retain your position on the ice if you break through. Access and prepare to use any other ice survival tools that you may have with you, including a knife, an ice pick, or ice rescue claws.
  • If ice thins, and you find yourself in a precariously thin spot, drop to your hands and knees to spread out your weight. You may even lie flat on the ice and crawl across.

    Survive a Fall Through Ice

    If you do break through thin ice, act quickly and follow these steps to safety:

    • Turn back towards the direction from which you came, as that ice is likely stronger than the ice ahead of you.
    • Break off any thin ice immediately in front of you, and use your trekking poles or other tools to help you regain your position on ice that will support your weight.
    • Plunge the blade of your knife, ice pick, or ice rescue claws into the ice in front of you so that you can use these tools to help you pull yourself back up onto the ice.
    • Once you are back on the ice, remain in a horizontal position, and move in a squirming motion until the ice is thick enough for you to move forward on your hands and knees and then in an upright position.
    • Once you’re back on solid ground, take immediate steps to get yourself dry and warm to avoid hypothermia and other cold-weather injuries.

      As temperatures get warmer, and you’re excited to get back out on the trails, be sure to check conditions with local rangers in order to avoid thin ice and other spring terrain hazards, including swift water, rockfall, snow-covered slopes, and loose terrain.