CalTopo pro tip - slope angle shading

If you're new to using CalTopo mapping software, watch this video tutorial to get started.

Note: this type of slope shading is made with an elevation model that may not show all relevant features and potentially hazardous avalanche slopes. It can be a useful tool for macro level trip planning, but is not accurate enough to completely assess potential avalanche hazard across all types of terrain.

Say you’re planning a canyoneering trip, climb, backcountry ski tour, or snowshoe trip.

Canyoneers want to locate possible waterfalls.
Climbers and skiers want to (hopefully) avoid potential avalanche slopes.
If you’re a good skier, you want to find a long run that’s reasonably steep but not ridiculous.
If you're on a long cross country hiking or climbing trip, you want to generally choose the path of least resistance and lowest angle slopes.

Good news, the best backcountry mapping software CalTopo has you covered.

Zoom into your favorite mountain area, and choose a base map.

Mouse over the map layer box in the top right corner, and click the drop-down next to Base Layer. I think the default map layer is MapBuilder Topo. This is my go-to map layer and a fine place to start, because it shows topography, contours, updated trails, and shaded relief.

Just under that you'll see some checkboxes in the category “Map Overlays”.

Check the box next to “Slope Angle Shading”, as seen below.

You should then see a color coded overlay added to your base map, showing approximate slope angle.

Yellow > orange, 27 to 35 degrees, low angle and pretty mellow, probably safe to travel on.
Red > purple > blue > black is 35 t o 60+ degrees, progressively steeper and possible avalanche terrain.

You can print this out, draw in a track of your intended route or import a GPX track you already have.

Canyoneers or photographers, looking for secret waterfalls? Find a stream drainage that goes over an area of blue/black. That's likely going to be a waterfall.

Here’s a view of the north side of Mt. Hood, with the Forest Service base map. Note the marked waterfalls on the map, that correspond with the stream running over an area of blue/black shading.