Fire moves more quickly uphill (slope) and has longer flames than on level ground or when spreading downhill.

The direction of the slope and the amount of sunlight an area receives also can impact fire behavior.

A chimney effect occurs when an area such as a drainage ditch, gulch, or ravine retains heat and channels wind, causing fire to burn even hotter and faster up the hill.
Ravines and gullies create chimney like paths on steep slopes
Know Your Risks
Threats From Steep Terrain