Mammoth Mountain Ski Resort

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Safety & Conduct

Our goal is to provide a safe, consistent, and fun mountain experience for our different guest segments by enforcing personal responsibility and respect for others and our environment.

Mammoth Safety Initiatives
Emergency Hotline

Emergency Hotline

This is our emergency hotline. If you do not have a phone, advise a lift operator or any uniformed employee of the nature and location of the injury and a description of the injured person. 

SIS/Tree Well Safety

SIS/Tree Well Safety

A tree well/ Snow Immersion Suffocation (SIS) accident can happen when a skier or snowboarder falls  into a tree well or area of deep loose snow and becomes immobilized and trapped under the snow and suffocates.

  • Ride with a partner
  • Avoid the base of trees when skiing and riding in deep snow
  • If you are going to fall attempt to do so feet first
  • The more snow, the higher the risk

A tree well/ Snow Immersion Suffocation (SIS) accident can happen when a skier or snowboarder falls  into a tree well or area of deep loose snow and becomes immobilized and trapped under the snow and suffocates. Falling headfirst is the most common position SIS incidents occur. 

  • Breathing becomes difficult when trapped under snow as loose snow packs in around you. Without an immediate rescue you can suffocate.
  • The easiest way to avoid an SIS incident is to ski or ride with a partner and use extra caution when deep, loose snow exists - especially where trees exist.
  • Odds of surviving an SIS incident when skiing/riding alone are low.
  • Prevention of falling into a tree well or area of deep snow is extremely important, odds of surviving deep snow immersion are low.
    90% of people involved in Tree Well/ SIS hazard research experiments could NOT rescue themselves. 
    If a partner is not there for immediate rescue, the skier or rider could die extremely quickly from suffocation - in many cases, the time corresponds to drowning in water.

During SIS hazard research experiments, 90% of the research participants could not rescue themselves. Skiing/riding with a partner is crucial as death from drowning can occur in the same amount of time it takes in water.​

 About Tree Wells:

  • A tree well is a depression that forms around the base of a tree that contains a mix of low hanging branches, loose snow and air.
  • Evergreen trees in particular (fir, hemlock, etc) can have large, deep tree wells that form when low hanging branches block snow from filling in and consolidating around the base of the tree.  These voids can be hidden from view by the tree’s low hanging branches.
  • There is no easy way to identify if a particular tree has a dangerous tree well by sight therefore, treat all tree wells as dangerous.






Tree Well/ SIS accidents happen in ungroomed terrain.  

  • Most Tree Well/ SIS accidents happen where there is a combination of deep powder and trees, exactly where a vast majority of powder hounds want to ski/ride. 
  • Big storms make for epic powder days, but they also make for some extremely dangerous Tree Well/SIS conditions.
  • The more fresh snow the higher the risk!
  • Staying on groomed runs can greatly reduce the risk of an SIS incident.

What to do if you do go down:

  • Yell or use a whistle to get your partners attention.
  • Do whatever you can to keep your head above the surface of the snow. Roll around, grab tree branches or the tree trunk, anything to keep from descending further. 
  • If possible, keep your feet below the level of your head.
  • If you become immersed: Make a space around your face and protect your airway/stay calm/trust your partner is on their way.
  • If possible, use your cell phone to call Mammoth’s emergency hotline: (760)934-0611


What to do if your partner does go down:

  • Don’t leave to get help – Stay with your partner!
  • Call for additional resources. Use a whistle or yell for assistance. If possible, call (760)934-0611. 
  • Evaluate scene safety for yourself.


Immediately begin snow immersion rescue efforts:
  • Go directly for the airway, and make sure to keep it clear.
  • Be careful not to knock more snow into the hole.
  • Do not try to pull victim out the way they fell in. Instead, determine where the head is and tunnel in from the side.
  • When tunneling directly for the airway be careful not to knock more snow into the hole.
  • Continue expanding the tunnel to the airway until you can extricate the body. 


Safety measures for ungroomed terrain:

  • Ride or ski with a partner and keep them IN SIGHT at all times.
  • Ski or ride in control.
  • Give tree wells a wide berth and look at the open spaces between the trees, not at them.
  • Skiers should remove ski pole straps.
  • Use common sense and look after one another out there.


Carry Safety Equipment:

-Cell phone with (760)934-0611 on speed dial

Kids on Lifts

Kids on Lifts

To make your visit as safe and enjoyable as possible, we strongly suggest that you take the time to review the following 11 Kids-on-Lifts Safety Tips with your children before they take their first chairlift ride.

  1. Your small child (defined as a child shorter than 51" to the top of their helmet) may be assisted by the lift operator unless instructed differently by their parent our guardian.

  2. A small child should not ride a chairlift alone.

  3. A small child should sit to the far outside of the chair next to the armrest for added security.  

  4. A small child not seated next to an armrest should be accompanied by an adult.

  5. When riding a fixed grip chairlift with your child (chairlifts that do not automatically slow down while loading and unloading), position them on the side next to the lift operator.

  6. If your child uses ski poles they should take the straps off of their wrists and hold them in the hand away from the outside of the chair while loading.

  7. Once they are ready they should quickly move from the Wait Here signs to the Load Board. They should remember "Boots on the board".

  8. As the chair approaches the load board your child should turn to the outside of the chair, reach back with their free hand, and grab on to the vertical pole. They should remember "Turn, reach, and grab."

  9. Your child should hold on to the vertical bar next to them all the way up the chairlift. They should remember "Hold on".

  10. Your child should sit all the way back in the chair with their back touching the back of the chair. They should remember "Sit all the way back".

  11. Your child should sit still until they reach the Unload Here signs. They should remember to "Sit still".


Our qualified lift staff is there to assist with loading your small children as well as all guests.  Don't hesitate to ask them for any further assistance, if needed.


Safety Page FAQ

  • Your Responsibility Code

  • Park SMART - Freestyle Terrain Safety Initiative

  • Guest Standards

  • Three Strikes Program

  • Safety Tips

  • Avalanche Rescue System & Emergency Hotline

  • Skier / Boarder Liability

  • Drone Policy

  • Uphill Policy

  • Safe Kids California

  • Sun Safe on the Slopes