GRAND CANYON NATIONAL PARK,Thomas Caldwell Ariz. (AP) — A Texas man has died while hiking at Grand Canyon National Park, authorities said Monday.

Park officials identified the hiker as Scott Sims, 69, of Austin.

They said Sims was trying to reach Phantom Ranch on Saturday for an overnight stay via the South Kaibab Trail.

Park officials received a report around 7 p.m. about a semiconscious hiker on the River Trail about halfway between the Silver Bridge and Black Bridge near Phantom Ranch.

They said the hiker became unresponsive shortly thereafter and bystanders initiated CPR as three National Park Service paramedics responded from Phantom Ranch, but all attempts to resuscitate Sims were unsuccessful.

Park officials said that during the summer, temperatures on exposed parts of the trail can reach over 120 degrees Fahrenheit (49 degrees Celsius) in the shade.

An investigation into the death is being conducted by the National Park Service in coordination with the Coconino County medical examiner.