Wildfires can burn and spread differently depending on what vegetation they burn. The two fires in northern Arizona have varied landscapes. Ponderosa pine trees grow near the North Rim of the Grand Canyon and can live for hundreds of years.

A wildfire burning in Grand Canyon National Park triggered a chlorine gas leak Saturday afternoon after flames reached a water treatment facility.

The Grand Canyon is vast, covering 1,218,375 acres and 1,904 square miles across Arizona. Here's what to know.

A wildfire that tore through a historic Grand Canyon lodge and raged out of control Monday had been allowed to burn for days before erupting over the weekend, raising scrutiny about the National Park Service's decision to not aggressively attack the fire right away.