39 CROWN FACE PROFILE NEW SNOW WIND SLAB NEAR-SURFACE FACETS CRUST RELATIVE HARDNESS DEPTH IN INCHES
40 Burial Point
41 Victim was buried 5-6 feet deep!
42 WEATHER Is the weather affecting the snow stability? Snow and Rain Wind Temperature
43 Wondering what the winter will be like?
44 More Snow Equals More Avalanches!!
51 LIONHEAD AREA, WEST YELLOWSTONE, MT April 4, 2001
52 Victims Track
53 Crown is 6-8 feet deep
54 PATH Snowmobile Victim 75 Feet
56 BURIED 2 FEET DEEP
57 SNOWPACK Could the snow slide?
60 Surface Hoar
61 Faceted Snow
62 HENDERSON MOUNTAIN, COOKE CITY, MT February 4, 1992
70 HUMAN FACTOR Are you willing to make an objective assessment of the avalanche danger?
71 CALL YOUR LOCAL AVALANCHE CENTER
73 Pay Attention To OBVIOUS Signs of Instability These include collapsing, cracking or “whumphing” of the snow, and…
74 Recent avalanche activity
75 Snowmobiler highmarking adjacent slope Investigating avalanche from day before
76 Yesterday’s Slide Path Everyone is facing uphill, engines off, with nowhere to run.
77 Investigating crowns can give you valuable information about the snowpack!
78 Test Small Slopes
79 Poorly executed highmark
80 Descending a slope from the top is safer than riding up from the bottom
81 Ride the slope one at a time!!
82 63% of snowmobile avalanche accidents occur while highmarking Bottom Line: if you’re going to highmark don’t expose more than one rider at a time on the slope
83 Don’t ride up to help out your stuck buddy!!
84 CARRY RESCUE GEAR!! Or better yet…make sure your PARTNER has rescue gear!
85 KEY POINTS Ride the slope one at a time. Don’t ride up to help dig out your stuck partner. Ride the slope one at a time. Don’t ride up to help dig out your stuck partner. Recent avalanches are an obvious sign of instability, so don’t play on adjacent slopes blindly. Test lots of small slopes on your way in and get off the packed trail as much as you can. Get off your machine and walk around occasionally. Riding a slope from the top down is a safer option than from the bottom up, because you are facing a better direction if anything goes wrong.
86 If the goal is to highmark then gather as much information as possible on initial passes by riding low and fast and not getting stuck. Turn away from the center of the slope. If the goal is to highmark then gather as much information as possible on initial passes by riding low and fast and not getting stuck. Turn away from the center of the slope. If you’re at the bottom waiting your turn and can’t avoid sitting in a big runout zone, keep your machines running and pointed away from the slope for a fast escape. Carry rescue gear on you and know how to use it.
87 Putting it all together… Recognize that patterns exist based on elevation, aspect and slope angle!
88 SAFE TRAVEL Slope angle, aspect with respect to sun and wind, consequences, slope shape, trees, runout, elevation, patterns of avalanche activity…
90 Created by: Gallatin National Forest Avalanche Center US Forest Service National Avalanche Center Photographs courtesy of: Doug Chabot, Tom Evans, Ron Johnson, Lance Reik,Karl Birkeland, Bruce Tremper, Scott Schmidt, Ian McCammon, Don Bachman, Doug Fesler/Jill Fredston and CAIC. Special thanks to Doug and Jill for using their Terrain/Weather/Snowpack method from Snow Sense.