Colorado, Arapaho Glacier—On July 18, Mrs. Karen Cowperthwaite (19), and her husband David (22) and Richard Raymond (21) attempted to climb the slopes of South Arapaho Peak.
It is not known whether they had reached the saddle or not, but a summer storm, common in the area, struck them not far below the saddle. They took shelter from the rain under the overhanging side of a large boulder, some 8 feet by 15 feet, close to the trail, at about 12,480 feet elevation. They wore light summer clothing and carried no spare clothing.
As they were sitting under the rock, apparently one, David Cowperthwaite, moved away from the rock to fix a broken shoe lace. When the lightning struck, it killed the other two instantly; they were found under the rock in a sitting position. Cowperthwaite was burned by the lightning on his buttocks and feet, where he had contact with the ground. He evidently jumped to his feet, leaving his boots behind, and ran straight down the slope, not following the trail. Just below the site of the accident the slope steepens suddenly and drops to the valley floor, 1500 vertical feet below. Cowperthwaite’s body was found in the valley floor, some 100 feet above the trail there. Apparently he stopped to rest and died of exposure and shock.
Rescue procedure: Raymond’s parents reported him overdue to the Boulder police at 5:30 next morning, but the information was so scanty that the Rocky Mountain Rescue Group was not called. The Group learned indirectly of the missing people at 11:00 a.m. and began a search. A team was organized at noon and left the Picnic Area at the end of the road at 2:45 p.m. At 4:15 p.m. they found the bodies of Raymond and Mrs. Cowperthwaite hidden behind the rock, some 20 feet south of the trail. Because the third person was nowhere to be seen, they radioed the State Patrol to alert the entire Rescue Group for a full-scale search. Meanwhile they searched the area including the peak itself (S. Arapaho). They found a pair of climbing boots 50 feet downhill from the accident scene; with this clue they concentrated the search downhill, and later found the body of David Cowperthwaite 1500 vertical feet below the accident scene, close to the main trail to the Fourth of July Campground.
Source: Ed Anderson, William Davis.
Analysis: The victims were not on the ridge when the lightning struck, but in a relatively flat area. A boulder-strewn slope descends gently from the “saddle” below S. Arapaho Peak, then steepens and plunges very steeply to the valley. The profile of the slope is convex; the lightning struck in the region where the slope suddenly changes. Apparently the lightning struck within 50 feet of the victims, and the discharge flowed over the rock where they were sheltering, then jumped the spark gap between the lip of this rock and the ground. The victims were found sitting directly under the overhang, in this “spark gap.” All indications were that they were killed instantaneously. The third person, sitting about 10 feet in front of the rock, was probably stunned as the electricity continued along the ground, to judge by the burns found on his buttocks and feet.