Detailed Accident Report

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Date: 2004-10-30
Submitted By: WWAN
Place: Sphinx Mountain, Madison Range
State: MT
Country: USA
Fatalities: 2
Summary: 2 climbers caught, carried, and killed

Sphinx Mountain Avalanche – 10/30/04

Weather and snowpack

Some light dustings of snow began accumulating in southwest Montana by late-September. More snowfall began in mid-October, with Moonlight Basin Ski Area reporting about 10 inches of new snow. The most significant snowfall to date arrived on the night of 10/28/04. On Friday the 29th, the Yellowstone Club Ski Area’s automated weather station was showing 9 inches of new snow with 16 total inches on the ground at 9,400 feet elevation (approximately 5 miles south southwest of the accident site). Big Sky reported “up to 20 inches of new snow”, but this was not measured at any particular site. Moonlight Basin reported 10 to 14 inches of new snow with strong westerly winds. Moonlight also reported a number of avalanches including a few size R3 natural slides (SS-N-R3) that were breaking out up to 2 feet deep and running most of the way down their paths. Big Sky reported one small avalanche triggered by a snow groomer.

Witnesses on Sphinx Mountain on the day of the avalanche accident reported cold temperatures, strong winds, and significant windloading. Wind speeds were estimated to be a steady 25 MPH with gusts to 35 MPH.


On October 30th, 2004 a group of three ice climbers set out to climb the north face of Sphinx Mountain, which is located approximately 8 miles south-southwest of Lone Peak in the Madison Range of southwest Montana. Two other separate groups of ice climbers would start on the trail behind them. The first group reached the saddle between Sphinx Mountain and the Helmet, which is at about 9000 ft elevation and is northwest of the Sphinx. They then walked up the ridge up the Sphinx and began traversing around to the north face. To do this traverse, climbers must cross several small steep bowls and slopes. One member of the party stopped to adjust his boots. When he came around the next corner he found the tracks of his partners going into where an avalanche had released. The tracks entered the slide about 10 feet below the crown face of the slide, which had a fracture estimated to be about 1 to 2 feet deep. The slide had gone over the cliffs immediately below, which are shown in the photo.

The third party member retraced his steps and worked his way over to where the avalanche had run over at least two cliff bands, which dropped approximately 200 or more total vertical feet. One victim was deceased, and the other was seriously injured. At some later point (perhaps one or two hours later) the second team heard yelling below them. This team consisted of two people, and one of them was an EMT. They were hiking above the saddle, but had not yet started traversing over to the north face. They quickly worked their way back down and over to the victims. They confirmed the one deceased victim and attempted to aid the second victim, who was unconscious and unresponsive. During this time the third party arrived and a person from that party was sent to the trailhead to try to get a helicopter for the injured victim. Soon afterwards, the second victim’s heart stopped beating and the rescuers began CPR.

Meanwhile, the winds continued to blow strongly and there was significant windloading. The rescuers heard one small avalanche that released off the Helmet, and within five minutes they heard another larger avalanche in a similar location. Since the wind was continuing to load the slopes above them, they feared for their own safety and eventually decided that the best course of action was to retreat from the scene, which they did sometime around noon. The helicopter was eventually dispatched and arrived at the scene two to three hours later, but they could not reach the victims.

On October 31st, Madison County Search and Rescue and U.S. Forest Service personnel responded to the scene to retrieve the bodies.

Report by: Karl Birkeland, Avalanche Scientist, Forest Service Nat’l Avalanche Center

Orthophoto of the accident site:

Topo map of the site:


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2 climbers killed in avalanche near Ennis

Associated Press

ENNIS - Two mountain climbers were killed when an avalanche swept them off Sphinx Mountain near here, Madison County officials said Sunday.

The victims were identified as Nathaniel Stevens and Bryan Nelson, both 25, of Missoula.

"The slide took them down," said Sheriff's Deputy David Clark. "They weren't totally buried. They took two 30-foot falls."

Witnesses said the men fell 30 feet to a ledge and then fell another 30 feet to the bottom, Clark said.

A third climber, Justin Elliott, also of Missoula, was not caught in Saturday's avalanche because he had stopped to tighten his boot, Clark said.

The three men were intending to ice climb and were traversing the north side of the mountain, which is in the Lee Metcalf Wilderness southeast of Ennis in the Madison Range.

Clark said the avalanche occurred about 9:30 a.m. Saturday during a snow storm, and it may have been triggered by overhanging snow cornices breaking off. Clark said authorities were notified about three hours after the accident.

Four separate parties were on foot in the area intending to ice climb and one of them included an emergency medical technician, who was able to reach the victims and determined they were dead, Clark said.

Air and ground attempts to retrieve the bodies Saturday failed, Clark said, and officials used horses on Sunday to bring out the bodies.

U.S. Forest Service officials said some areas had heavy snow and strong winds on Thursday night.

"That's what created the current avalanche conditions," said avalanche scientist Karl Birkeland of the Gallatin National Forest Avalanche Center.