What are natural pathways that fire often follows first with increased intensity?

The correct choice, saddles, refers to low-lying areas between higher ground, which can create a funneling effect for fire, allowing it to spread more rapidly and with greater intensity. When fire encounters a saddle, it can be influenced by the topography to flow through that area, accelerating its movement due to the convergence of heat and wind patterns. The shape of the land can naturally direct the fire's path, which leads to increased intensity in these locations.

In contrast, canyons and ridges also play roles in fire behavior, but they tend to have varied effects depending on the fire's direction and environmental conditions. Canyons can funnel wind and create unique fire behavior; however, they typically can produce more varied fire growth patterns rather than always following a predictable path. Ridges can also act to influence wind patterns, but they may not serve as direct pathways for fire the way saddles do. Lakes, on the other hand, are barriers to fire spread due to water's natural extinguishing properties, resulting in less intensity rather than increased.