In briefThere were 71,655 rock climbers and mountaineers in the Grand Teton National Park from 1970 to 1980, and there were 144 accidents and 30 deaths. Because all climbers are required to register with park officials before climbing, accurate incidence rates can be determined. There were two accidents per 1,000 climbers per year, and this rate remained stable over the ten-year study period although the number of climbers increased. Characteristics associated with accidents included being the lead climber, ascending very steep rock, being inexperienced, and making errors in judgments. Fatal accidents appeared to be associated with travel on snow.