ALBUQUERQUE, N.M. (AP) — U.S. land managers are racing the clock as hotter, drier weather raises the risk of wildfires in the nation’s overgrown forests with each passing year.

Wildfires burning at or near the Grand Canyon's North Rim are still raging as strong winds, high heat and low humidity persist.

In this secluded paradise, mail still arrives by mule, turquoise cascades tumble into travertine pools, and time flows at the pace of the river.

A new emergency system for the Grand Canyon is getting life-saving messages to people with little cellphone service.

A combination of high winds, dry air and above average temperatures caused a wildfire in the Grand Canyon to rapidly expand and cause major damage.

Fire activity on the North Rim of the Grand Canyon has forced the closure of several trails and campgrounds. Meanwhile, life goes on at the South Rim where tourists endured a smokey visit Monday.

The NWS warning was in effect for regions of the Grand Canyon below 4,000 feet elevation. Temperatures were forecast to potentially reach 110 degrees at Phantom Ranch and 102 at Havasupai Gardens.

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.