ACCIDENT REPORT: HATCHER PASS / SUMMIT LAKE, ALASKA
Prepared by: Kip Melling, Alaska Mountain Safety Center and Anchorage Nordic Ski Patrol
Date of Accident: Sunday, November 11, 2001 @ approximately 2:50 p.m.
Accident Location: Hatcher Pass/ Summit lake area of the Talkeetna Mountains at located in Hatcher Pass (Elev. 3,888 ft.) at MP 19.6 Fishhook Road (2 miles west of Hatcher Pass Lodge).
Synopsis: Two snowshoers traversing a small, but steep, leeward slope triggered a small hard slab avalanche which partially buried one person and completely buried and killed the other.
The Avalanche: The size of the avalanche was relatively small by Alaskan standards. Measuring 84 ft. across the crown. The hard slab debris varied in size, from as big as a kitchen table to as small as a trash can lid. The fracture line varied in depth from 8 in. to 12 in. The flanks were measured between 4 in and 8 in. The avalanche traveled 210 ft. from the crown face to the toe of the debris which terminated in a deep trough. Debris depth in the deposition zone ranged from 3 ft. and 6 ft. and consisted of pencil hard slab blocks intermingled with unconsolidated faceted snow.
Background Weather and Snow Conditions: The first measurable snow blanketed the Talkeetna mountains starting in late October (approx. 10/22). Automated station data retrieved from a National Weather Service site located at Independence Mine, elev. 3,450 ft, 3 miles away, showed little or no precipitation after 10/22. Temperatures ranged from +9 F to +29 F over the period leading up to the incident. Two significant wind events, one on 10/31 and another on 11/3 were recorded and observed by local skiers. During these events, isolated wind slabs formed over faceted snow. The weather on the day of the incident was calm, clear, and sunny with temperatures in the mid 20’s.
Terrain Factors: The accident site consists of a steep concave-shaped slope covered with alpine tundra and small rocks unsuitable as anchors. The northerly aspect is commonly leeward, and thus wind loaded, releasing naturally throughout the season. Slope angles within the starting zone ranged from 32-38 degrees (measured), with less steep angles above the crown (an area of convexity). The slope was generally steep, smooth, and uniform, with a terrain trap (a deeper depression) in the runout zone. A road to the Summit Lake parking area is sometimes used as a winter access trail to a popular area called April Bowl, where two previous avalanche fatalities occurred (a skier in 1994 and a snowboarder 1997). A third avalanche fatality (a snowmobiler in 1999) occurred on the opposite side of the valley above the access road and numerous other close calls have been reported over the years.
The Accident: On Sunday afternoon Travis and Becky Patton, age 30, left their car at the Hatcher Pass Lodge for a day of snowshoeing. Traveling with two dogs, a husky and blue heeler, they climbed the 2 miles up Fishhook Road toward Hatcher Pass (maintained in the summer only). Exploring the area around Summit lake, they turned around to begin their return trip back to the parking lot. At 2:50 p.m. The two traversed across a steep slope, 200 ft above the Summit lake access road. Travis was in the lead, with Becky following 5 ft behind. (It’s unknown where the dogs were at the time of slide.) Travis proceeded out onto the slope for 10-12 steps (with Becky close behind) and “started to feel like he didn’t belong there.” As he turned around to go back, the slope started to move. Both he and Becky were caught in the moving debris. For the first 150 ft., Becky was sliding on the surface on her stomach with head uphill and feet downhill. As she reached the runout zone, the debris apparently spun or flipped her onto her back with her head downhill and the snow capped over her. Travis was able to stay on top of the moving debris, only to be buried up to his thighs. He dug himself out, only to see Becky was nowhere to be found.
The Rescue: Travis estimated that he searched for 5-10 minutes using only his MSR snowshoe as a probe. At 3:00 p.m. he ran 200 yards to the pass and started yelling for help. At 3:02 p.m. Kip Melling, an avalanche instructor with the Alaska Mountain Safety Center/ Anchorage Nordic Ski Patrol and ski partner Terri Pauls, a trained patroller also with the Anchorage Nordic Ski Patrol, were climbing Fishhook Road just below Hatcher Pass. Both were out for a day of skiing. A man came into view and was yelling “Avalanche!, Help, avalanche!” A
s soon as they were notified of the situation, Melling yelled down to two young snowboarders, also hiking the road below him, to go to the lodge and notify the park ranger. Pauls and Melling then proceeded to climb the remaining grade to the pass. When they met Travis 5 minutes below the pass, he was winded from running and had two dogs with him. Gathering all the witness information, the three skied and hiked the short remaining distance to the site.
He described the accident site as being just on the other side, near the Summit Lake parking lot. The three arrived on site at 3:10 p.m. Travis stated that, neither he nor Becky were wearing an avalanche transceiver. The only avalanche equipment they had was a probe, which Becky had in her pack. With no surface clues, the witness established the Area Last Seen (ALS). The search, using probes, ski poles, and skis, was concentrated on the left (east) side of debris. The debris came to rest in a trough, 210 ft. directly below the fracture line. The depth of the debris varied from 2-6 ft. and consisted of blocks of hard slab packed among unconsolidated facets.
The blue heeler dog (Barley) was sitting on the debris. Travis was asked by Melling “Who owned the dog?” When Travis said it was Becky’s, the searchers immediately started to probe that area. After 10 min. of unsuccessful spot probing, the witness was again asked “Where were you when the avalanche started?” He pointed to an area to the right of the slide. Where the set of tracks lead into the slide, Travis estimated he took 10-12 steps traveling from right to left (west to east) before the avalanche let loose. The trajectory (about 150 ft. above the debris) was estimated by Melling and the rescuers re-directed their efforts to that area. After 5 probe advances, Melling hit a snowshoe with his probe.
At 3:25 p.m., Travis and Melling started digging with shovels, excavating approx. 3 ft. of wind slab and faceted snow. At 3:30 p.m. park ranger, Pat Murphy arrived with a snowmobile/sled, and 4-6 other area skiers and snowboarders. The digging was relatively easy with only faceted snow and a 12 in. wind slab to move.
The total time to remove the victim and gain an airway was 10 min. Becky was found laying on her back head downslope, face up, with snowshoes and pack still attached. She had been under the snow for 40 min. The victim was driven by ambulance to a hospital in Palmer 25 miles away and later transferred to Providence hospital. She was taken off life support Tuesday morning at the request of family members.
Contributory Factors:
Terrain: Steep (38 degrees) at the starting zone. Leeward, smooth, convex and concave with little or no anchoring. A terrain trap (a deep trough) in the run out zone.
Weather: Previous weather created a wind slab on top of a weaker layer of faceted snow. Current clear sunny weather without snow, created a false sense of security.
Snowpack: Clues to instability were obvious in the area. A natural slide, which had been passed by the victims, had occurred on a very similar slope of the same aspect 100 ft. away. Wind scoured ridges, wind textured gullies and recent skier/snowboarder triggered avalanches were evident form the route. A thin early season snowpack was instrumental in creating an unstable weak layer of faceted snow. Wind events during the two prior weeks had created a shallow, but dense wind slab which could be easily detected.. The only element missing was a trigger.
Human Factors: Neither Travis or Becky had any avalanche training, knowledge, skills to evaluate avalanche hazard or perform a rescue. The rescue equipment they carried was inadequate and buried with the victim. The proximity of the road, an early season shallow snowpack, and the blue-sky weather may have contributed as a lure to the backcountry. During the rescue, Travis spoke of joining an outdoor group and getting some avalanche training this season.
Conclusions: An early season snow followed by generally cool temperatures created a persistent faceted weak layer. A weak layer such as this can remain deep within the snowpack for long periods of time. The strength of the snowpack and the stress it could withstand was easily detectable. Obvious avalanche activity in the area, was created by recent wind events. The fact that the accident occurred within 10 min. time from two trained avalanche rescue people was very fortunate, but still did not alter the outcome for the victim. The rescue was carried out efficiently and methodically, with little or no wasted effort. The medical support which followed, was commendable, as was the effort by EMS personnel. An organized group effort would have taken hours to organize and carry out. This effort was carried out in minutes. A good example of how the window of survival is very small, when buried without air. Thus, enforcing avoidance and preparedness.
***MEDIA REPORTS***
By Jeff St. John, Anchorage Daily News (Published: November 14, 2001)
An Anchorage woman has died after being caught by an avalanche and critically injured Sunday afternoon in Hatcher Pass. Rebecca Patton, 30, was declared legally dead Monday at 2 p.m. at Providence Alaska Medical Center, Alaska State Troopers spokesman Greg Wilkinson said. She was taken off life support at 6:45 a.m. Tuesday after family members arrived at the hospital, he said.
Patton and a friend had climbed up the road from Hatcher Pass Lodge and were snowshoeing high on the Willow side of the pass when a small wind-slab avalanche gave way beneath them. She was carried about 150 feet by the avalanche and buried about 3 feet deep in a bench at the base of the slope. Her friend was unhurt. Patton had no pulse and was not breathing when found about 40 minutes after the slide, said Kip Melling, one of the rescuers. Patton was carrying a probe pole, the only piece of rescue gear she and her friend had, he said. “This could have gone the other way if both people were trained, not only in avalanche recognition but in avalanche rescue,” Melling said.
Avalanche risk is high in Southcentral Alaska this year because of shallow snowpacks and cool temperatures, said Doug Fesler, co-director of the Alaska Mountain Safety Center. He said backcountry travelers should carry and learn to use avalanche rescue gear and should learn and follow basic avalanche safety rules. Local woman seriously hurt in avalanche
SNOWSHOE: Victim was buried for 40 minutes at Hatcher Pass.
By Ben Spiess, Anchorage Daily News (Published: November 12, 2001)
An Anchorage woman was critically injured in an avalanche Sunday afternoon in Hatcher Pass. The 35-year-old woman, whose name has not been released, was snowshoeing with a male friend at 3 p.m. when a small wind-slab avalanche released beneath them, according to state parks rangers and witnesses. The slide carried the two about 100 yards down the slope. The man came to rest on top of the snow.
The woman was buried, head-down, three feet beneath the surface, said rescuer Kip Melling of Eagle River. The woman was buried for 40 minutes, Melling said. Rescuers immediately began CPR. State park ranger Pat Murphy took the woman to Hatcher Pass Lodge by snowmobile, where an ambulance picked her up at 3:50 p.m. and took her to Valley Hospital in Palmer. Sunday evening, the woman was transferred to Providence Alaska Medical Center in critical condition.
The woman is the first avalanche casualty of the season. A foot or more of snow across Southcentral Alaska has lured people into the backcountry early this year. Large avalanches have cut loose in Turnagain Pass, in the mountains near Anchorage and in Mat-Su. Sunday’s accident underlines the deadly potential of the smallest avalanches, said Melling, who is an avalanche expert. The victim and friend left their car at Hatcher Pass Lodge on Sunday afternoon and followed the road up past Summit Lake to Hatcher Pass, said state park ranger Dennis Heikes. They and their dogs were traversing a north-facing 32-degree slope high on the Willow side of the pass when the slab, 120-feet wide and 12 inches deep, cut loose beneath them, Heikes said. Moments before the slide, the man had become concerned about snow conditions and the pair had turned around, Melling said. They were about five feet apart on the slope, he said.
Melling, who teaches avalanche safety with the Alaska Mountain Safety Center, described the pitch as a perfect avalanche trap: a wind-loaded slab on top of a thin, unconsolidated layer that was on top of a firm bottom layer. At the top, the slope was 38 degrees — optimum steepness for a slide. The pair were in the middle of the slope when it released, Melling said. The snow traveled about 100 yards before piling up in a natural bench at the base of the slope. The woman slid on her belly, facing uphill, Melling said, but was quickly buried in debris. The man stopped on top of the debris, he said. Melling and his girlfriend, Terri Pauls, were ascending on the other side of the pass when they heard yelling.
The man “was just frantically waving his hands, yelling Avalanche!’ Help, avalanche!’ It didn’t seem real,” Melling said. The victims had no avalanche rescue gear except for one probe, which was buried with the woman, Melling said. He told two snowboarders in the area to go to Hatcher Pass Lodge for help. Then Melling and Pauls pulled out their probes and began a random search in the debris. Forty minutes after the slide they found the woman. She was not breathing and had no pulse, and her lips were blue. Melling, Pauls and the man began CPR. Meanwhile, Park ranger Murphy arrived on a snowmachine. They loaded the woman onto a sled and took her to Hatcher Pass Lodge, where an ambulance picked her up.
The last time Melling saw the woman, she was unconscious with no pulse. When told the woman was still alive hours later, he was shocked. “I almost can’t believe it. “The lesson here is that even though it seems like there is no snow, it’s still dangerous. A small slide can have a tragic ending,” he said.
