Wyoming, Grand Teton National Park, Teewinot. On 10 August, Fred C. Jacobs (21) and four companions were descending Mt. Teewinot after a dual attempt on the summit via two different routes (2 in one party and 3 in the other). The party was regrouping after the lateness of the day forced both parties back off their routes. Jacobs was about 75 feet below two of his companions when one of them dislodged a rock which struck him on the forearm. Jacobs was able to return to the valley under his own power.
Source: Rick Reese, Park Ranger, Grand Teton National Park.
Analysis: The party should have been on the alert as to the location of all members of the party, particularly with darkness setting in.