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Show AVALANCHE DATA Due to rapidly rising avalanche hazard, the Little Cottonwood Canyon highway was closed at 10: 00 a. m. on 22 January. Skiing was permitted on minimum hazard slopes served by the Wildcat Lift; however, the lift was shut down at 3: 00 p. m. due to increasing hazard. During the high hazard situation on 24 January, everyone ( except those participating in the control program) was restricted to the lodges. Prior to 24 January, large climax slides ( SS- AA- 4 & 5) were released by gunfire on High Rustler, Lone Pine and Stonecrusher. Blind firing at Baldy Cirque and Shoulder released a very large and destructive sttde ( SS- AA- 5) from the center of the Cirque which overran upper Main Street and Mambo and descended with terrific force clear into lower Mambo, a zone normally classified as minimum hazard. Extensive timber destruction indicated a strong wind blast action. A fast moving slide ( SS- N- 4) descended the Little White Pine gully sometime on the morning of 22 January, blocking the road. Several natural slides also ran on the lower slopes of Peruvian Gulch about this time. The northeast slopes of the knoll adjacent to the Race Course Saddle slid back to the ground sometime on 23 January, ( SS- N- 3), the first time a slide has ever been observed at this site. The accumulation of a 51- inch snowfall on the unstable base brought the hazard situation to a critical point by the morning of 24 January. Most of the major slide paths had not yet slid. Immediate and vigorous control measures were undertaken to insure releases while area and highway traffic were under supervision. When firing began, it became obvious that the snow was even more critically unstable than first estimated. Messengers were dispatched to the various lodges instructing everyone to remain inside and to be prepared for large aval anches from the north side of the canyon. Firing began shortly after dawn with a 75 mm howitzer. Climax avalanches were released from Baldy Shoulder and Cirque, the largest setting up a dust cloud which filled the entire head of Collins Gulch. A shot on Superior released a slab avalanche which ran across the road. The howitzer was fired several times on the Hell Gate and Cardiff targets, but no slides were dislodged. The first shot at Flagstaff Bowl released a major climax avalanche from the entire basin. This avalanche descended the usual slide- path gully at high velocity, struck and partially overran the rock knoll west of the guard station, was deflected slightly to the west, and landed along the east side of Peruvian Lodge and in the east edge of the Peruvian Lodge parking lot. A number of vehicles were buried in the parking lot, and one jeep was overturned. One attendant and two guests at the lodge failed to heed safety measures imposed before the firing began. The attendant was in a snowcat belonging 113 |