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of page 6). Slope processes were also accelerated. Peak unit area dis- charge from side slopes is estimated to have been as high as 9,000 c.f.s. per square mile. Landslides and rockfalls must have been common although most of their deposits have been subsequently removed by fluvial processes. The storm cost 139 lives (with 5 persons still missing in mid-October) and an estimated 28.8 million dollars in damage. In the Big Thompson Canyon 316 homes were totally destroyed and 73 received major damage; 56 . I I I I mobile homes were lost and 52 businesses destroyed. Yet, conditions could I well have been far more severe. Flood peaks on the mainstream and North Fork were not synchronous. The North Fork peaked at 9:40 pm (approxi- mately 8,700 c.f.s.) some 40 minutes after the mainstream had peaked at Drake, which is located at the confluence. Furthermore, Dry Gulch, a small watershed of approximately 4 square miles near the head of the Big Thompson, received extremely heavy precipitation. Its flow eroded 6,000 cubic yards of material from the base of Olympus Dam which holds back Lake Estes. Had the dam failed, damage would have been increased by orders of magnitude. The storm has left a legacy of increased hazards due to undercutting of banks and over steepening of slopes. Following the flood, the city of Estes Park lost much of its tourist business and has suffered great eco- nomic loss. Likewise, the number of visitors to Rocky Mountain National Park has markedly decreased since the flood. Late in the evening of July 31 the storm moved northward and pro- duced high intensity rainfall and somewhat more minor flooding in Rist Canyon, Soldier Canyon, and the canyon of the Cache la Poudre River. The northernmost record of the intense storm is the 10.5 inches of rain which fell in a few hours in southern Wyoming near the Colorado border. 4 I I I I I I I I I I I I I