Cal Fire spokesman Henry Herrera described the multitude of conditions that fuel the flames of the monster Caldor Fire as it continues to burn over the Sierra Nevada mountain range and threaten the resort of South Lake Tahoe, California.

“Everything has lined up, perfect recipe for a major fire like this,” Herrera said during an interview Wednesday evening in CNBC’s “The News with Shepard Smith”.

“The topography is very steep, very rugged, the winds were strong … we had gusts of up to 35, 40 mph on the peaks of the ridge tops. The winds are perfectly aligned with the canyons, which is really pushing the fire with them a rapid rate of spread. “

Firefighters struggle to contain the flames as they head for the southern tip of Lake Tahoe. Herrera, who was back and forth at the front of the Caldor Fire, explained other factors that contribute to the massive fire. This includes embers that ignite dry vegetation miles before the fire, which in turn creates new, small “point fires” that grow and combine with the main fire.

The Caldor Fire burned more than 200,000 acres, which is larger than the entire city of Memphis. It has also forced tens of thousands of people to evacuate. Herrera told host Shepard Smith that firefighters are working to save homes and communities and are currently focused on the northeast end of the fire around Meyers and South Lake Tahoe.

“We have built containment lines to keep the fire from entering these areas,” Herrera said. “We are building emergency lines, areas in case the fire crosses these containment lines, and so far we have successfully kept the fire out of the communities.”