Tree wells—deep pock­ets of soft snow that form at the base of tree trunks—are one of the most dan­ger­ous aspects of back­coun­try ski­ing, and are the lead­ing cause of non-avalanche-relat­ed snow immer­sion deaths (NARSID). Over the last 20 years, tree well immer­sion has claimed the lives of more than 70 skiers and snow­board­ers; sad­ly, each fatal­i­ty was com­plete­ly pre­ventable. Here are a few tips to help you avoid tree wells and stay safe in the back­coun­try.

Tip #1: Check the weath­er report

Tree wells are formed when trees with wide, low-hang­ing branch­es pre­vent snow from con­sol­i­dat­ing around the base of the trunk. As a result, tree wells are often dif­fi­cult to dis­cern from the com­pact­ed snow that builds up between trees. For this rea­son, most doc­u­ment­ed NARSID inci­dents occur after heavy snow­fall, when tree height is tougher to deter­mine with the naked eye. As tempt­ing as it may be to ride fresh back­coun­try pow­der, you may want to avoid unmarked runs (and ungroomed edges of estab­lished trails) if sig­nif­i­cant snow­fall has accu­mu­lat­ed dur­ing the pre­vi­ous 24 hours.

Tip #2: Trav­el with at least one bud­dy

If you insist on vis­it­ing the back­coun­try after fresh snow­fall, then you should do so with at least one oth­er adult who is strong enough to extract you from a tree well. Vis­i­ble con­tact is cru­cial; indi­vid­u­als who fall into a tree well can die from asphyx­i­a­tion with­in min­utes. If your part­ner falls into a tree well, do not leave them to seek help. In most cas­es, the vic­tim will be buried head­first; deter­mine the loca­tion of your part­ner’s head, tun­nel in to cre­ate an air­way that allows them to breathe, and make sure there isn’t any snow in their mouth.

Tip #3: Don’t pan­ic

Worst-case sce­nario: you’ve stum­bled into a tree well head­first and your part­ner isn’t there to dig you out in a time­ly man­ner. Experts say the most impor­tant thing to do in this sit­u­a­tion is remain calm; if you strug­gle, the depres­sion will deep­en and you will like­ly sink fur­ther into the snow. Cre­ate breath­ing space between your face and the snow, and then rock back and forth to widen the space. Take short, inter­mit­tent breaths to con­serve oxy­gen and, if pos­si­ble, place a call for help on your cell phone.

Tip #4: Car­ry the prop­er equip­ment

The fol­low­ing tools great­ly reduce the risk of death if you or your part­ner hap­pen to fall into a tree well.

Whis­tle: Keep a whis­tle handy just in case you fall into a tree well and your part­ner did not see you fall. Remem­ber: the clos­er it is to your mouth, the eas­i­er it will be to access if you fall head­first into the soft snow.

Shov­el: Dig­ging a prop­er tun­nel by hand is near­ly impos­si­ble. For this rea­son, every­one in your par­ty should car­ry a snow­shov­el when rid­ing in the back­coun­try.

Avalanche Bea­con: In the major­i­ty of tree well acci­dents, the vic­tim is at least par­tial­ly vis­i­ble, but some­times the well is so deep that he/she can­not be seen. An avalanche bea­con will help res­cue crews locate the vic­tim in either case (espe­cial­ly the lat­ter).

Avalanche Probe: This tool can effec­tive­ly locate some­one who is com­plete­ly immersed in the snow. How­ev­er, it is some­what use­less if the mem­bers of their par­ty do not know exact loca­tion of the crash site. But if no oth­er options are avail­able, prob­ing all the tree wells in the gen­er­al area may be the vic­tim’s only hope.

RECCO Reflec­tor: This item can be tracked using a RECCO device, which is car­ried by most ski patrol mem­bers in case of such emer­gen­cies. If your part­ner goes into a tree well and you know he or she is car­ry­ing a RECCO reflec­tor, be sure to let res­cue ser­vices know if and when you need to con­tact them.

AvaL­ung: One of the most inno­v­a­tive snow res­cue tools on the mar­ket, the AvaL­ung is a breath­ing appa­ra­tus that draws oxy­gen direct­ly from the snow­pack. While the device will not afford long-term sur­vival, prop­er use can enable the indi­vid­ual to breathe with rel­a­tive ease for more than an hour. In Jan­u­ary 2011, back­coun­try ski­er Peter Lev sur­vived a near-fatal tree well acci­dent thanks to his AvaL­ung. Most of these devices cost less than $150.

Tip #5: Under­stand that abil­i­ty is irrel­e­vant

This won’t hap­pen to me because I’m an expert, you might say. But please note that more than 80 per­cent of fatal­i­ties relat­ed to snow immer­sion involved advanced skiers/snowboarders, many of whom had exten­sive back­coun­try expe­ri­ence. Tree well acci­dents can hap­pen to any­one, in the back­coun­try or on groomed trails. Thank­ful­ly, you can mit­i­gate much of the risk by acknowl­edg­ing risky weath­er con­di­tions, trav­el­ing with at least one part­ner and remain­ing in con­stant visu­al con­tact with them, equip­ping your­self with the prop­er gear and remain­ing calm if you do fall into a tree well.