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Maps Calculating Steepness

Nate Woodward sent us this very
interesing topographic map application that lets you pull up any topo map in the country and then overlays the map on the screen with different colors telling you the steepness (in degrees) of the slopes. Backcountry skiers, snowshoers, and mountaineers wanting to consider the avalanche hazard of terrain they plan to visit will find this particularly useful for evaluating a route. We've embedded this map application into our 'Maps' tab above and to the right so you can quickly access this system any time you want.

Use these maps along with weather and avalanche forecasts to help determine the avalanche hazard of slopes you plan to ascend, descend, or traverse.
  • Slopes that are a dull grayish green are below 20 degrees in angle.
  • Kelly green slopes are 20 to 27 degrees steep.
  • Yellow slopes are 28 to 34 degrees steep.
  • Red slopes (the most dangerous ones for avalanches) are 35 to 45 degrees.
  • Purple/blue slopes are 46 degrees or steeper.

Click here for a full-screen view of this application. The easiest way to navigate the full-screen maps is to click the binoculars (upper right) and then enter a place (e.g., 'Blewett Pass, WA' or' Mission Ridge, WA').


Note: If any of you are using other on-line map tools that are particularly valuable for your outdoor sports, please recommend them as a 'comment' below.