How to Prepare to Thru-hike in a High Snow Year
Thru-Hiking and backpacking tips for navigating snow in the Sierra and San Juan mountains on the PCT, CDT, and JMT and beyond
April 13th, 2023
Thru-hikers sometimes opt to cross long stretches of “trail” that have been covered by snow while wearing or carrying skis. Here, the author traversed sections of the Continental Divide Trail on skis in May 2019.
Forecasts are predicting high snow pack in the Sierra Nevada mountains into July 2023. If you're a long distance backpacker, how should you prepare for thru-hiking in a high snow year?
Hiking in a high snow year can change what gear and skills you need to stay safe while backpacking. Despite the stunning views, the high snow pack introduces many new hazards that must be addressed such as traveling on icy slopes, navigating without a visible hiking trail and crossing swollen rivers.
I am a long-distance hiker who has thru-hiked in big snow years, and I also work as an educator teaching Wilderness First Aid and on topics like risk assessment. In this article, I will go over some of the hazards thru-hikers, backpackers, and section-hikers may see in a high snow year in the Sierra Nevada and San Juan mountains. We will cover some things you can do to prepare yourself beforehand, options for structuring your hike, and what gear you may want to carry.
For thru-hikers heading out on trails like the Pacific Crest Trail (PCT) or the Nüümü Poyo (John Muir Trail) and Wonderland Trail around Mt Rainier that regulate start dates with a permit system, knowing how to safely travel across snow becomes even more important as hikers may run into snow early in their hikes and before conditions are ideal. Some of these tips may also be useful to early Appalachian Trail hikers navigating North Carolina in February or March as well as Colorado Trail and Continental Divide Trail thru-hikers.
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Crossing rivers swollen with snow melt is one of the biggest challenges of thru-hiking during a big snow year.
Tips for Snow travel
Although it technically may be summer, in a high snow year, you may encounter some winter hiking conditions. Having to hike long distances on snow can slow you down, use more energy for each mile and often requires more risk assessment. Elevation gain may require more energy than at lower elevations, too.
Even if you started the trail solo or hiked other portions of the trail by yourself, plan to stick with a group for the high snow portions of your thru-hike.
Travel with a group
When traveling on snow and crossing rivers, it is often best to travel as a group--whether winter hiking or hiking in the summer in a high snow year.
Being in a group allows you to help each other because there will be people around to assist with a rescue and provide first aid if something goes wrong. When you are traveling in snow, you can rotate who goes first so that you can share the labor of breaking trail or cutting steps. That way you can spread out the exhausting job of going first. For river crossings you can also work together to make them safer for everyone. Along the PCT, many groups form at Kennedy Meadows, the last resupply town before entering the Sierra.
We will talk a bit more about groups throughout our snow travel tips. To learn more about traveling with a group, like what the ideal group size is and how to make decisions safely in the backcountry with a group, check out our article on risk assessment and decision making.
In high snow years, the trail may not be visible for many miles. Thru-hikers will need to learn how to navigate through the mountains without a trail.
Types of Snow and Time of Day
You will have to consider snow quality. For certain, more challenging portions of the hike, consider what time of day you want to hit the snow so that it is the best quality for hiking.
Northern slopes in the morning
On northern slope angles or in the morning, the snow can be firm or occasionally have a thin ice crust on the top from melting and refreezing. Conversely, when the snow is in the sun for a long time, such as in the afternoon or on the south side of a slope, it can become slushy and make it challenging not to slip on steep climbs.
SUN CUPS
You may also run into something called sun cups, which is snow with mounds and pockets that can be incredibly frustrating to hike on.
POSTHOLING
In soft, deep snow, you will likely posthole. Postholing is where your foot (and sometimes whole leg) sink into the snow; it drastically slows progress and is very tiring. It is also possible to hit rocks, logs, water or ice when you punch through deep snow. If there are obstacles under the snow and you punch through, you can scrape yourself, lose or damage gear, or twist, even break, your ankle.
When post-holing, think about potential hazards under the snow, use waterproof socks or gaiters to lessen how wet your feet get, follow the boot pack (footprints of those before you) if possible, and rotate who is leading.
Some hikers find that wearing long hiking pants instead of hiking shorts makes postholing less likely to chafe their skin.
Example of a snow bridge from the PCT, a place where a creek is melting underneath snow.
Snow bridges
Like post-holing, being aware and looking out for snow bridges is also essential.
Snow bridges are snow that crosses the water. When they are firm, thick, and strong, snow bridges can be incredibly useful and ease river crossings. When they begin to thin and melt, though, they can become quite dangerous.
If you punch through the snow because it is not strong enough to hold your body weight, you can end up in the water. The rivers under snow bridges are typically very cold They are also often swollen and incredibly fast-moving because of all the snowmelt. Rivers can sometimes continue under snow, creating an area where a fallen hiker could get trapped.
Be sure to test snow bridges, especially during high melt, or find a different place to cross the river.
To test snow bridges, first look at them to see if you can see on obvious thinning in the snow (if it looks thin, do not cross), then you can use your trekking pole to test the thickness and sturdiness, if you put your weight on it start with one foot first to be sure it holds, make a plan for if it does break and do not cross if you are alone. This is one of the reasons we recommend thru-hikers carry trekking poles.
Winter traction, Self arrest, and ice axes
When hiking on high slope angles, it is best to be prepared to fall because the snow can be slippery. You can use winter traction devices like microspikes, ice grippers, or crampons to help decrease the risk of falling and can learn different techniques for walking safely with traction.
You should also be carrying an ice ax and know how to self-arrest. When crossing a steep slope, look at what is at the bottom of the slope. If there are rocks, trees, crevasses, or ice, it is a hazardous area to fall, it is even more important to have your ice ax out. Many people who run into trouble are carrying an ice ax on their pack, but don’t have it out. I learned this the hard way once crossing a small patch of snow by Sonora Pass without an ice ax out with boulders in the runout and got very lucky that I was all right.
Once you have two feet on the snow, you can still slip. So even if it is a short distance, have your ice ax out if the runout is dangerous.
Boot pack steps
Sometimes when snow is too hard or icy, you may need to cut steps using your ice ax. Use your tool to cut out semi-flat platforms to step on as you go. Following boot pack can help you have platforms for your feet; just be sure it’s going the right way and make wise choices for the current conditions.
On some descents, when the run out is safe, you may be able to glissade (slide on your butt) down, which can be much faster, safer, and more fun. To glissade, wear long pants or rain pants so you don’t cut yourself on the snow, take off any traction on your feet and get out your ice axe. Have your ice ax in a position where you can use it to break and to self-arrest if you lose control. Practice glissading with a winter course before attempting on a thru-hike and always be sure to check for obstacles at the run out before going.
Make good decisions
Remember, you don't always have to ascend a steep or icy slope. You can choose another route or come back later. This is especially relevant for optional side trips. For example, many PCT thru-hikers choose to climb Mt Whitney or hike down to Yosemite Valley. CDT thru-hikers may hike the Rocky Mountain National Park loop. However, if conditions are not ideal, it may be a good idea to skip those side trips. Sometimes, it is a good choice to take alternate routes. We get into this more in our article on risk assessment and in our section below on structuring your hike.
Despite not being able to see a trail when navigating in the snow, you may be able to see the boot pack. Here, the author navigates the Sierra Nevada range on the PCT in 2017, a high snow year.
Navigating on Snow and Trailless travel
If you are snow hiking, you often will be without a trail to follow because the snow will cover the path. You must know how to navigate through the mountains without a trail. Just as in winter conditions, there will be times when the best way to go is a little different than where the trail would have gone; sometimes, this can save a lot of time because it allows you to cut out curves or switchbacks. It may also be the safest to avoid steep areas.
Other times, when climbing a steep slope, you may need to add even more switchbacks. You will also often have to break trail, which can involve post-holing and navigating and can be pretty exhausting. Be sure you switch off who is leading.
Finding other people’s footsteps can be a great gift, but be sure you don't mindlessly follow. The boot pack could be old, and the conditions may have changed drastically, so following the exact boot pack may be unsafe now. It is also important to remember to check your navigation; not all footsteps lead to where you want to go.
The author wears a sun hat, bandana, and long sleeve sunshirt as well as sunglasses and plenty of sunscreen when thru-hiking in the snow.
UV exposure
Sun protection is also important in the snow because the snow will reflect a lot of the light. Beware that some people get sunburns inside their mouths and nostrils if they hike with their mouths open. Wearing a neck gaiter that you can pull over your mouth and nose guard are ways to protect yourself against this. The nose guard is great! But it does not really protect against nostril burns, just protects against nose sunburn on the outside
Snow blindness, a typically temporary loss of vision due to the intensity of the light, is also a concern. Be sure you have good sunglasses with adequate coverage and other sun protection. Sunscreen, sun hats, bandanas, and sun-protective clothing to cover yourself can also be helpful.
For more on what to wear winter hiking, see our article by Arlette Apple Pie Laan.
When the trail is snow for as far as you can see, look for “islands” of rock that are dry for potential camping sites. Alternately, find lower elevation campsites.
Camping on snow as a backpacker
Camping on snow can require different skills than camping at lower elevations. In our guide to how to get started winter camping, we address some of these differences. The skillsets you need are even more important to learn as a backpacker or thru-hikers.
Snow stakes
You may need snow stakes to set up your shelter, especially if you are not carrying a free-standing backpacking tent. The stakes that come with most backpacking tents may not stick in the snow depending on the conditions.
If you can find dry ground to set up your tent, that will typically be best. If not, compact a spot in the snow and camp there. Be sure you have the gear to keep yourself adequately warm. To avoid these issues, many hikers carry a freestanding tent for snow travel. They may use snow stakes for extra support.
Campsite selection
When picking a camping spot, it can be warmer under trees, which can be nice in cold weather.
Be aware that if there is a storm in the forecast, trees can get covered in snow and become snow loaded. This can sometimes cause them to dump a lot of snow down on you and your shelter. Your shelter can also get snow loaded in big storms. If this happens, you may need to get up throughout the night and shake the snow off. If your shelter only has steep angles such as pyramid tents, the snow will often just fall off, and you may not need to do this.
Sleeping cold
While sleeping on snow or backpacking at altitude, you will feel colder at night. Many thru-hikers pick up a sleeping pad with a higher r-value (insulation rating) or a sleeping bag liner (or both) before entering the San Juan Mountains or Sierra Nevada range. Our guide to Shoulder Season Backpacking Gear has recommendations for gear for late-season thru-hikers, but similar tips apply to thru-hikers in a high snow year.
Beware frozen shoes
It is common for backpackers to take off their wet shoes for the night and leave them outside their tent. However, in winter conditions or cold weather at higher altitudes in the summer, you may find your hiking boot frozen solid in the morning. You may find your laces are frozen and you can't get your foot into your shoe.
I knew a hiker who would put his shoes under his sleeping pad to elevate his feet at night and keep his shoes warmer and drier.
Frozen water filter
Similarly, in cold weather, your water filter may freeze overnight. If you are using a water filter like a Sawyer Squeeze or Katadyn Be Free, this will make it non-functional. Before going to bed, empty as much water as you can from your filter and put it in a plastic bag. Bring it inside your tent. You may even want to double-bag your filter and put it inside your sleeping bag. This can be an issue not only in high snow years and at higher altitudes, but also at lower elevation areas as well. Always check the temperature before going to sleep and protect your water filter. I always sleep with mine in my sleeping bag so that I don’t need to track if the temperature is going to drop below freezing.
Protect electronics
Cold temperatures drain batteries. This can be an issue especially with cell phones. Before you camp, keep your cell phone warm and consider keeping with your cell phone in your sleeping bag. Some backpacking quilts, like those by Katabatic Gear, specifically have a phone pocket for this reason.
PROTECT MEDICATIONS
Some medication can also be sensitive to changes in temperature (such as epinephrine or insulin), so be aware if you carry any meds. Check with your medical professionals to determine if your medication can tolerate cold temperatures. Talk with them about solutions to protect your medications. For example, we know of folks who hike with it in a pocket near their body and sleep with it in their sleeping bag.
Have a way to melt snow into Water
Though you are surrounded by water, you need to be sure that you can turn that snow into water for drinking and cooking. During winter conditions, your planned water sources may be buried, frozen, or your slow travel speed doesn’t allow you to get to them at your anticipated time. Having a cooking pot and backpacking stove is essential for melting snow; some people also like to bring heat-safe water bottles to put their hot liquids in. If you are a thru-hiker who has been stoveless up until the Sierra or San Juan mountains, this is the time to pick up a stove.
Check for unsafe snow conditions, avalanche danger, and melt-freeze cycles. The author saw this while thru-hiking the Wind River High Route.
Hiking in Winter Conditions
Be ready for changing winter-like conditions such as storms, avalanche danger, melt-freeze cycles, and melt and high rivers. Bring an extra day of food for snowy sections in case of a storm or needing to turn back.
Check conditions before you go
Check the conditions before you go—the weather forecast, avalanche forecast, snow depth, and other hiker reports about the trail condition from those who are ahead of you. The National Park Service and National Forest Service sometimes also have more up-to-date information, especially backcountry rangers stationed along the trail. A backcountry ranger can tell you about lingering cornices, river fords, or other details that may not show up on online resources.
Be ready for a slower search and rescue response if you need help and the conditions are not good. High snow years are high water years, which means high understory growth years. Understory plants catch fire more easily, which can counterintuitively lead to high fire years later in the season.
Some suggestions for where to check conditions are the local avalanche forecasting center’s website or social media, postholer.com, NOAA weather, and the SNOTEL monitors on Caltopo.
The FarOut app that many thru-hikers use for navigation also has a comments section where hikers who are ahead of you on the trail can share snow conditions and snowmelt conditions on creeks and rivers.
Ice axe skills, snow travel, and self arrest are all good skills to practice before you leave for your thru-hike.
Skills to learn and practice
Snow travel and self arrest
Snow travel and self-arrest are critical skills to learn during the winter and spring before heading out in a high snow year. They are skills that will keep you from falling and help you save yourself if you do fall. You can learn these by taking a course, reading about them, and watching videos online.
Be sure you are consulting a good resource and be sure you practice as muscle memory is key to being able to use them in an emergency. If you already have snow travel and self-arrest skills, practice them on a low key winter hike before heading out on your thru-hike.
Navigation
Navigation is another essential skill to learn and practice in the winter and spring before starting a backpacking trip. You can use a mix of in-person courses, online resources or books. It is best to feel comfortable navigating with a map and compass as well as a GPS. While many hikers use FarOut Guides app on their phone, I recommend bringing paper maps as extra navigation tools during high snow sections.
As with snow travel and self arrest, many backpackers find it helpful to take a refresher course or get out and practice before starting a backpacking trip in a big snow year. You can also read on backcountry travel in winter to orient yourself on what to pay attention to.
Wilderness First Aid or Wilderness First Responder
The winter or spring before your hike is an ideal time to take a Wilderness First Aid (introductory course) or Wilderness First Responder (more advanced course) training. This helps you learn how to respond to emergencies in the backcountry. They teach you to keep yourself safe in an emergency, treat life threats, and improvise care until help arrives. Learning how to provide basic medical care drastically increases your safety and your group's safety in the backcountry.
If you are in the Bay Area, check out one of my Wilderness First Aid classes in San Francisco! Otherwise, if you live in other parts of the world, many REI stores or local outdoor schools will offer these classes.
A reflection on a frozen lake along the trail.
Avalanche Course
Taking an avalanche course certified through the American Institute for Avalanche Research and Education (AIARE) is also a great choice for a high snow year. Usually, you can take their courses on either skis or snowshoes during winter months before your hike.
An AIARE level I course will help you learn to read avalanche reports, avoid avalanche terrain, and look for signs of a potential avalanche. It will teach you how to respond and make decisions. This course can help you decide whether it is safe to do a particular section and how to mitigate risks while you are out. These courses are available around the world.
If you've taken an AIARE Level 1 course before, it's worth taking a refresher course before going out in a big snow year.
Typically, people traveling in the backcountry in the winter or spring take an avalanche course and either a Wilderness First Aid or Wilderness First Responder course. The avalanche course teaches you how to find people under the snow, whereas the wilderness medicine courses teach you how to treat their injuries afterward.
If you can’t take an AIARE avalanche course this year, check out this online course as well as the resources on AIARE’s website (it is not a substitute for an in-person class but shares some useful safety knowledge).
Although it isn't a substitute for a class, you can also read REI's advice on:
Water safety or swift water rescue
Some people also take white water safety or swift water rescue courses. These courses are instrumental in learning how to assess water and what to do if someone does get swept.
Most importantly, do not get in the water where someone got swept. You can try throwing something to them, reaching for them or pulling them out downstream. Many people get injured or die going into the water after someone who is in trouble.
Snow camping
Snow camping is something you should practice before you go. You can find many online resources and courses covering the basics of camping in the snow and more advanced snow camping skills. Unless there is an emergency, you will likely only need to know how to camp on snow. Learning the skills of digging a snow trench or making a snow cave can help in emergencies but should not be required. You will also learn how to read snow conditions.
You can learn about winter camping basics in our article on How to Get Started Winter Camping or in REI's Winter Camping Basics guide.
Extra Gear for Hiking in Big Snow Years
Though your skills and experience are always the most important thing in keeping you safe, the gear you bring can also play a significant role in safety. I bring different gear when I am hiking in snowy conditions than I do otherwise. Here are some gear items I consider bringing when preparing for a snowy section.
For more information, see our guide on How to Dress for Winter Hiking.
Safety
Ice ax
Traction/snow travel (one of the following)
Skis & climbing skins
Hiking poles or trekking poles that fold down so you can switch to an ice ax when necessary
Foot care
Waterproof socks– can be paired with trail runners to keep your feet insulated from the cold wetness of the snow, you will still get some of your own sweat, but it will not be as cold
Snow gaiters–can help keep snow from getting in your shoes
Clean & dry socks to sleep in
Some people switch from trail runners to hiking boots, others don’t– I typically used trail runners often with waterproof socks for snowy conditions. Winter boots, which have extra insulation but can be heavy and bulky, are usually not necessary for summer travel on long trails even in high snow years. However, many hikers find a waterproof hiking shoe or lightweight hiking boot with waterproofing can provide extra warmth. Just be aware that these take longer to dry out fully when wet.
Warmth
Layer your clothing and keep some dry options (baselayer top and bottom, fleece jacket, puffy jacket, hat, lightweight winter gloves, etc.)
Snow stakes
Waterproof layer (rain jacket) and waterproof layer (rain pants or rain kilt)
Waterproof backpack protection
Lighter
Waterproof matches
Navigation
Paper maps
Compass
GPS
Avalanche Terrain Specifically (minimum required equipment)
Shovel
Beacon (Avalanche transponder)
Probe
See our guide to How to Get Started Backcountry Skiing for our recommendations for avalanche terrain specific gear.
The author at the Colorado-New Mexico border on the CDT in May.
Structuring your hike
In addition to the skills you can learn and the gear you can carry to make your hike more successful and safe, there are also different ways to structure your hike. Structuring your hike around snow pack, the current trail condition, and weather can allow you to decrease your risk significantly. It is also ok if you change how you structure your hike while you are in the middle of hiking.
Here are some hiking structures hikers often use when hiking:
NOBO: Hiking from South to North in one direction (permit required for start dates for the PCT)
SOBO: Hiking from North to South in one direction (currently no permits required for this direction for the PCT)
Flip-flop: Hiking half of the hike either NOBO or SOBO and then switching halfway to hike the other half in the opposite direction
Flipping: going to hike a different section or going hike somewhere else along the trail in a different direction and coming back later that season, completing all sections
Skipping: skipping over a part of the trail and going to hike a different part of the trail without coming back for it later
Section hike: Hiking a section of a longer trail, for example, the Oregon portion of the Pacific Crest Trail
LASH: Long A$$ Section Hike, hiking a long section of trail or hiking almost all of the trail
Delaying: staying somewhere and waiting to continue your hike, going on a side trip and coming back, or starting later than you had originally planned
Going Slow: taking your time while you hike to let conditions change
Bailing: deciding that something is too dangerous or that conditions are not good and choosing to not continue on. Someone may continue thru-hiking despite bailing on a particular day, on a particular section, peak, or river. They may even choose to come back to a section after conditions improve.
Quitting: deciding this year, this trail, or this project is not for them and going home
Thru-hiking on snow can take a lot more energy than hiking on dry trail. Create expectations that allow for slower travel and being tired and allow your body to rest and recover and to find joy in the experience. Here, the author is making a snow angel. Remember that even though it may be challenging, there is room to have fun.
Takeaways
This outline of the increased hazards in a high snow year, skills you can learn to increase your safety, the gear you can bring, and ways you can structure your hike will help you create an enjoyable and safe hike. These are meant to be tools for you to use to prepare as we head into an extremely high snow year.
It is unlikely for you not to see any snow if you are doing a higher elevation, long-distance hike in the southwestern U.S. in 2023. Since you will likely see snow, this can hopefully help you prepare for it.
The author on the PCT in 2017.
About the author/why you should trust us
My trail name is Giggles, I am a long-distance hiker, and I work as an educator teaching Wilderness First Aid in San Francisco with my business, With The Wild Things. I am a Wilderness EMT, Leave No Trace Master Educator, Personal Trainer, California Naturalist, and I have my American Institute for Avalanche Research and Education (AIARE) I Certification.
I have hiked several routes (hikes with off-trail travel), such as the Sierra High Route (SHR) and the Wind River High Route (WRHR). I also hiked the Pacific Crest Trail in the 2017 high snow year and the Continental Divide Trail in the 2019 high snow year.
When I hiked the PCT in 2017, I went through the Sierra (in mid-June), whereas when I hiked the CDT in 2019, I decided not to hike through the San Juans (in mid-May). Instead, I hiked the San Juans at the end of my hike (early Oct).
