The NPS recommends avoiding hiking the Grand Canyon's inner trails between 10 a.m. and 4 p.m., when temperatures are at their peak. Temperatures in the inner canyon can reach over 120 degrees Fahrenheit in the shade, creating "extremely hazardous conditions for hikers," the NPS said.

A hiker has died on the South Kaibab Trail in the Grand Canyon National Park while attempting to reach the Colorado River.

In late June, a Grand Canyon National Park concessions employee contracted hantavirus, a rare but often fatal rodent-borne disease that plagues the American West, the National Park Service confirmed Monday.

A 67-year-old man hiking in the Grand Canyon National Park died on the South Kaibab Trail, below Cedar Ridge. Officials believed that extreme heat created hazardous hiking conditions. The Grand Canyon National Park Service said at about 11:50 a.m. July 8, the Grand Canyon Regional Communications Center received a report of an unresponsive hiker.

A 67-year-old Texan planning to spend a night at Phantom Ranch on the floor of Grand Canyon National Park collapsed and died while hiking down the South Kaibab Trail.