How to Choose the Right Ski Trail for Your Level: A Guide to Trail Ratings

As you’re learning more about skiing, once you get on the hill, the next thing to learn is how to choose the right trail for your skill level and preferences. Ski maps and signs have colorful symbols, such as green circles, blue squares, black diamonds, and more, to show ski trail ratings at a glance. But what do they actually mean? And how do ski run ratings compare across national ski areas in North America?

In this article, we will explain the basics of the North American trail rating system. This system indicates difficulty levels based on slope, width, grooming, snow conditions, and other factors.

We will also explore the regional and resort-specific differences you should be aware of, as well as the historical reasons behind some unique designations. By the end of this article, you will have a better understanding of how to choose the right ski trail for your level.

Just as a warning, though (and every trail map says this): trail ratings are RELATIVE to all the other trails only within that resort. For example, a black diamond in the Midwest is NOT the same as one in Colorado. We always recommend warming up on green or blue trails before working up to more advanced terrain, especially at a resort that you are not familiar with.

A quick aside about angles and gradients

Before we explain the trail rating system, we need to briefly introduce two ways to measure a slope's steepness: angle and gradient. The angle is the measure of how far a slope tilts from the horizontal, expressed in degrees. For example, a flat surface has an angle of 0 degrees, while a cliff has an angle of 90 degrees. Most skiing occurs on slopes from 2-25° for regular runs, and up to ~45° on expert trails. On the other hand, gradient is the measure of how much the slope rises or falls over a given distance, expressed as a percentage or a ratio. For example, a slope that rises 10 meters for every 100 meters of horizontal distance has a gradient of 10% or 1:10. Both angle and gradient are useful for describing the difficulty of a ski trail, but they are not equivalent. For example, a slope at 45 degrees has a gradient of 100%, while one at 60 degrees has a gradient of 173%. Therefore, it is important to understand both measures when comparing ski trails.

Ok, one other aside about average and max steepness

By time you get to the end of this article, you will realize that there is quite a bit of subjectivity in rating ski slopes. We also need to consider the difference between average and maximum slope.

Average slope is what you usually see in the legal definitions (yes, the states and provinces have their own definitions) listed below for how to evaluate steepness (e.g., 25% grade). However, within that average 25% grade, there could be a small few-hundred-foot section that is closer to 40%.
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If we rated that small section on its own, it would be a blue square, or an intermediate trail. The resort gets to decide whether it is rated based on the average or maximum, among other factors (e.g., grooming, trail width, other trails it accesses, etc.), so there is a legitimate argument either way. This is just another reason it can be tough to compare similarly rated runs not only between resorts, but within them as well.

Green Circle (aka Beginner Trails)

The green circle is the symbol for the easiest difficulty level, suitable for beginners and novices. These beginner slopes are usually wide, gentle, and well-groomed, with a slope less than 25%. They are ideal for learning the basic skills of skiing, such as turning, stopping, and controlling your speed. They are also great for warming up, practicing, or taking a break.

Most ski resorts in North America have a large percentage of green circle trails, ranging from 20% to 50% of the total terrain. However, even green-rated trails can vary widely in difficulty. The designation includes runs from the “bunny hill” (aka learning area) to a more challenging top-to-bottom run. Despite their relative lack of difficulty, there are still some relatively well-known trails in North America, including:

• ‍Schoolmarm at Keystone (Colorado): This is a 3.5-mile-long trail that winds through the scenic mountain scenery and offers gentle slopes and wide curves. It is one of the longest green circle trails in the country and a great way to enjoy the views and the fresh air. It is also one of the first trails to open at Keystone each season, so you know that it will be available and well-maintained throughout the season‍
• Home Run at Park City  (Utah): This is a 3.5-mile-long trail that runs from the top of the Bonanza Express lift to the base area. It is a suitable place to graduate from after the bunny hill and has incredible views of the surrounding Wasatch mountains.‍
• Great Eastern at Killington (Vermont): This is a 4-mile-long trail that runs from the top of the Superstar Express Quad to the Skyeship base. It is a wide, gentle run offering scenic views of the surrounding peaks and valleys. It is a perfect choice for beginners who want to experience the thrill of skiing from (nearly) the top of the mountain, without the pressure of steep or crowded slopes. It is also a terrific way to end your day, cruising through the lower forest on your way to the car. Just note that you are not near the main base, which will require taking a gondola and a quad lift back to have access to the main base areas via either Snowshed slope or Highlander.

Blue Square: Intermediate Trails

The intermediate ski run rating represents the most common trail at most resorts, suitable for progressing beginner skiers who have mastered the basic skills and are ready for more challenge and variety. You will generally want to be making proficient parallel turns to feel comfortable on these slopes. These trails are usually steeper, narrower, and more varied than the green circle trails, with a grade of 25-40%. They occasionally have moguls, bumps, trees, or ungroomed sections that require different techniques than groomers. They are ideal for improving your confidence, endurance, and versatility on the slopes.

Most ski resorts in North America have a similar percentage of blue square trails as green circle trails, ranging from 20% to 50% of the total terrain. This classification, unfortunately, also starts seeing a wide variety of difficulties for the same rating, both within and between resorts. For example, a blue square trail in Utah might be more challenging and adventurous than one in New York, due to deeper snow and more varied terrain. We recommend asking locals or staff which runs they would recommend based on your skill levels. Here are some more notable blue square runs:

• ‍Riva Ridge at Vail (Colorado): This is the longest run at Vail, spanning over four miles and dropping over 3,000 feet. It technically starts as a black diamond-rated run at the top, but about 1/3 of the way down, the Trans Montane catwalk cuts across it, and it becomes a legendary blue run. If you skied the whole thing, it would take you right down the heart of the resort and back to the main base‍
• Ruthie’s Run at Aspen (Colorado): This is a classic run that offers stunning views of the town of Aspen and the surrounding mountains. It essentially follows the lift line of Ruthie’s, a rare high-speed triple chair, and serves as a World Cup downhill course each year. It is a fun run that is always groomed and features some fun faces and rolling terrain. Very lap-able.‍
• Elk Park Meadows at Big Sky (Montana): This is a fun run with some widely spaced trees and immaculate grooming off the Thunder Wolf 4 chair at the lower part of Andesite Mountain. It is a great spot to take a few warm-up laps, alternating between this run and the Super-G course feel of nearby Big Horn, also accessible from the Thunder Wolf 4 chair.‍
• Jester at Sugarbush (Vermont): This is a long and scenic run that starts from the top of Lincoln Peak and descends for over two miles, offering panoramic views of the Mad River Valley and the Green Mountains. It is a challenging run with a steep, narrow start, followed by a series of curves and dips that keep you on your toes. Jester is one of Sugarbush's signature trails and is often used for racing and training events. It is usually groomed but can also have some bumps and natural features along the way. If you are looking for a thrilling and rewarding run, Jester is an excellent choice.

Black Diamond: Advanced Trails

Now we’re starting to get to the spicier terrain. The black diamond ski slope rating, aka “Most Difficult,” is suitable for skiers with a higher level of skill and experience (“advanced”) who are looking for more thrill and excitement. These trails are steeper, narrower, and even more varied than the greens and blues, with a grade of 40% or more. This is also where you will start seeing less grooming on the trails, although most resorts will still groom a select few. You are also more likely to find obstacles on these runs, including trees and moguls. Getting to be a proficient skier of black diamond runs will really open the mountain to you, as you’ll be able to visit almost every area.

Most ski resorts in North America have a smaller percentage of black diamond trails than green circle or blue square trails, ranging from 10% to 30% of the total terrain. These trails are usually more focused near the resort's summit, but that is far from a tried-and-true rule. As we get into the more difficult terrain, snow quality starts to matter more, and can have a huge impact on how difficult the run skis. For example, a hard-packed and icy slope with moguls will ski more like a double black diamond trail, but that same run covered in 6” of fresh powder would be significantly easier to navigate. Keep an eye on conditions and ask some locals while you’re there how these runs are skiing. Here are some of the more notable examples:

• ‍Castlerock Run at Sugarbush (Vermont): This trail is classic New England skiing. It is a tight and popular line that is rarely groomed, meaning it will give your quads a workout. It is one of the signature runs in the Castlerock pod, which exclusively relies on natural snow to open. It also offers spectacular views of the Mad River Valley and the Green Mountains.‍
• Dave Murray Downhill at Whistler Blackcomb (British Columbia): This trail is named after the Canadian ski racer who won a bronze medal in the downhill event at the 1980 Winter Olympics. It is also part of the men's downhill course for the 2010 Winter Olympics, and features large sweeping turns, mostly consistent fall lines, and fun rollers that test skill and endurance. It can also be considered a “Hollywood” run as the lower half of the run goes right underneath the lift line of the Creekside Gondola. Try to hit this one in peak season, as its lower elevation makes it more susceptible to early- and late-season warm temperatures and/or rain.
• ‍Ptarmigan at Lake Louise (Alberta): This trail is one that can be an excellent introduction to black diamond skiing out west. Generally wide open and often groomed, it descends the backside of Lake Louise and offers multiple opportunities to try out some nearby tree runs that are also rated as black diamonds. The best part about the tree runs? Little commitment is needed, as you can bail out back to the main trail pretty easily. The run connects back to the Ptarmigan lift, making it easy to lap.‍
• Alf's High Rustler at Alta (Utah): This trail is named after Alf Engen, a legendary Norwegian-American skier who founded the ski school at Alta and pioneered many of the runs in the area. It also technically should be a double black diamond. It is a steep and narrow chute that drops from the top of the ridge to the base of the Collins lift, offering spectacular views of the base area and the far side of the Little Cottonwood Canyon. You can expect moguls all the way down unless there was a fresh dump of snow. So why is it listed as only a single black diamond, given its difficulty? It’s because Alta only has ratings up to a single black diamond. More on that a bit later.

The Double Black Diamond: Expert Trails

Double black diamond trails (aka “double diamonds”) symbolize the toughest runs at the resort. They are best suited to expert skiers with a high level of skill and experience who are comfortable navigating unmarked obstacles and variable conditions. If you can ski these trails, you could be considered an “all-mountain skier.”

These trails are usually the steepest, narrowest, and most varied of all, with gradients that can approach 100%. Other features you may encounter on these trails include cliffs, couloirs, cornices, trees, rocks, and moguls, which require more commitment. They are ideal for pushing your boundaries, exploring new terrain, and having an adrenaline rush.

Most ski resorts in North America have a small percentage of double black diamond trails, ranging from 1% to 10% of the total terrain. We might sound like a broken record at this point, but it bears repeating with this terrain: difficulty varies widely by region and resort, and even within the resort, depending on snow conditions.

For example, a double black diamond trail in Alaska might be more challenging than one in New Hampshire due to higher elevation and greater exposure. In addition, some challenging lines in low-snow years can be nearly impossible because exposed cliffs are covered over in higher-snow years, making the terrain more accessible. Getting some intel from the locals will be helpful here. Here are some examples of more notable double diamonds:

• ‍Corbet's Couloir at Jackson Hole (Wyoming): This trail is considered one of the most iconic and difficult inbounds ski runs in the world. It starts with a 10–30-foot drop (depending on snow conditions!) into a narrow chute that starts off steep and curves to the skier's left, followed by a series of moguls and rocks. It requires a lot of skill, nerve, and timing to land and ski this trail successfully. Although, to be honest, most of the challenge is in the entry. The rest of it opens up quite a bit and isn’t nearly as steep.‍
• Upper Cirque at Snowbird (Utah): This trail is the steeper section of a wide-open bowl that offers some of the best powder skiing in North America. It can feature a corniced entry, depending on snow conditions, but after that, the skier will only need to worry about steep, open terrain with potential unmarked obstacles for the next ~75% of the trail. A few trees pop up near the bottom before it reconnects with Chip’s Run. Enjoy the views of the Peruvian Gulch!‍
• The Wall at Kirkwood (California): This trail is a steep and exposed face that drops from the summit and is one of the resort’s classic descents. It has a consistent pitch of about 45 degrees and is almost always covered in moguls. Because of its exposure to wind, it often has icy, variable snow conditions, making it tougher to control your speed and direction. It is also a run right under “The Wall” lift, so everyone will be watching!‍
• The Palisades at Palisades Tahoe (California): This trail is a series of steep, rocky, and narrow chutes that run along the ridge line of the resort. You will do a short hike from the top of Siberia Express to reach this lift. Main and National are the most popular. Each chute has a vertical drop of about 600 feet and a slope angle of up to 55 degrees. It is a popular spot for expert skiers who want to showcase their style.‍
• The Front Four at Stowe (Vermont): This trail is a group of four legendary runs that descend from the top of the Fourrunner Quad. They are National, Starr, Liftline, and Goat, each with its own character and challenge. They have a vertical drop of about 2,000 feet and a slope angle of up to 40 degrees. They often have ice, bumps, rocks, and narrow sections, making them difficult and demanding. They are a classic destination for skiers seeking the best of New England skiing.‍
• Rambo at Crested Butte (Colorado): This trail is the steepest cut run in North America, with a slope angle of 55 degrees at the top and an average of 50 degrees throughout. It is a straight, narrow chute with exposed shrubs in lower-snow years that plunges about 1,000 feet. It has no grooming, no snowmaking, and no bailout. You will often see a sign at the top from the ski patrol letting you know what you are signing up for if you choose to drop in. It is a badge of honor for those who dare to ski it. The good news is that no one will see you if you fall and slide all the way to the bottom, since the lifts aren’t immediately overhead!

The Extreme Terrain: Um, is this still safe?

Ok....now we’re getting a bit wild. Also, I'm being dramatic. Most of these are double black diamonds, and outside Colorado, that’s what they’re rated. In general, the “EX” rating is Colorado-specific. These trails are probably best defined by the Colorado Ski Safety Act: “Extreme terrain means any place within the ski area boundary that contains cliffs with a minimum twenty-foot rise over a fifteen-foot run, and slopes with a minimum fifty-degree average pitch over a one-hundred-foot run.” Thanks, Colorado! In general, you can expect cliffs, chutes, crevasses, and/or other hazards.

Only a few ski resorts in North America have extreme terrain, and they usually require a special pass, a guide, or a helicopter to access. Some resorts specialize in extreme terrain, including Silverton Mountain (Colorado), Revelstoke Mountain Resort (British Columbia), and Alyeska Resort (Alaska). There is a lot of extreme terrain that is lift-accessible, and even more that is served by helicopters. If you are skilled enough to tackle this terrain, 1) well done! And 2) you are probably not SkiTutor’s core audience. That being said, if you aspire to be an expert skier (as I did), here are some areas to look at conquering:

• ‍The Steep Gullies at Arapahoe Basin (Colorado): These are a series of narrow and steep gullies that descend from the summit of the resort, offering some of the most extreme and technical skiing in the state. The slope angle can exceed 50 degrees, and the vertical drop is about 1,200 feet. They are accessible only by a traverse and require a 30-minute hike to return to the base. They are open only during high snow times, and skiers need to be prepared for variable snow, rocks, and cliffs.‍
• Delirium Dive at Sunshine Village (Alberta): This is a massive bowl of ungroomed snow, cliffs, chutes, and cornices that offers endless lines and variations for expert skiers. The slope angle can reach up to 60 degrees, and the vertical drop is about 2,000 feet. It is accessible only by a gated entrance that requires a transceiver, a shvel, and a partner. Don’t think that they will let you by if you aren’t fully trained in using that equipment. Practice before heading up! It is considered one of the most challenging and exhilarating ski runs in Canada.‍
• The Fingers at Palisades Tahoe (California): These are a series of narrow and rocky ridges that protrude from the top of KT-22 peak, resembling fingers. They offer some of the most difficult and exposed skiing in the resort, with a slope angle of up to 70 degrees and a vertical drop of about 800 feet. They are popular among daredevil skiers who want to test their skills and nerves, as well as spectators who can watch the action from the chairlift. They are named after Wayne Poulsen, the founder of Palisades Tahoe (nee Squaw Valley), who skied them for the first time in 1946.‍
• The Big Couloir at Big Sky (Montana): This is a long and narrow chute that drops from the summit of Lone Peak, offering some of the steepest and most sustained skiing in the country. The slope angle ranges from 40 to 55 degrees, and the vertical drop is about 1,500 feet. It is accessible only by a short hike from the ram, and requires a helmet, an avalanche transceiver, and a partner. It is one of the few runs in the US with a triple-black-diamond rating, a rating unique to Big Sky. Since you need to sign out with Ski Patrol, this is definitely only for the committed.

The Regional and Resort-Specific Differences: What to Look Out For

As you can see, the North American trail rating system is not a uniform or standardized system, but rather a relative and subjective system, that varies by region and resort. This means that you should not rely solely on the symbols to choose the right ski trail for your level, but rather use them as a general guide, and talk with locals or ski patrol about what best matches your ability level. Here are some of the regional and resort-specific differences that you should look out for:

• Colorado's Extreme Terrain: Colorado is the only state that has a legal definition of extreme terrain, which is any terrain with a slope angle of 50 degrees or more, or any terrain that is exposed to avalanches, rock fall, or other hazards. Ski resorts in Colorado are required to mark their extreme terrain and warn skiers of the risks involved. Some examples of extreme terrain in Colorado are Highland Bowl at Aspen Highlands, Lake Chutes at Breckenridge, and East Wall at Arapahoe Basin, among the other examples mentioned above.
• Big Sky's Triple Black Diamond: Big Sky Resort in Montana is the only resort that uses a triple black diamond symbol, which is reserved for runs they designate as “high exposure” above double black diamonds. These trails are usually located in the Headwaters and Lone Peak Summit areas, which are a steep and rocky terrain that requires hiking and traversing to access. Some examples of triple black diamond trails are Icehouse, Three Forks, and Firehole.

• Jackson Hole's Double Blue Square: Jackson Hole Mountain Resort in Wyoming is one of the only resorts that uses a double blue square symbol, which is used to indicate the intermediate trails that are more difficult than the regular blue square trails, but not as difficult as the black diamond trails. These trails are usually located in the Casper and Apres Vous areas, which are more challenging and varied than the beginner areas. Some examples of double blue square trails are Sundance, Werner, and Moran.
• Alta's Lack of Double Black Diamond: Alta Ski Area in Utah is one of the few resorts that does not use a double black diamond symbol, even though it has some of the most difficult and varied terrain in North America (Note: Palisades Tahoe was the same but added double black designations in 2022). Instead, it uses a single black diamond symbol for all its advanced and expert trails and relies on the skiers' judgment and discretion to choose the right trail for their level. Some examples of black-diamond trails at Alta include Alf's High Rustler, Greeley Bowl, and Catherine's Area.

Conclusion

Understanding ski trail/run/slope ratings and how they differ across national ski areas helps you choose runs that match your ability each day.

The North American trail rating system is a valuable guide for selecting trails suited to your skill level and preferences, but it isn’t always precise. Ratings can vary by region and resort. Snow conditions and your familiarity with the mountain are just as important, if not more so, when picking a run. Be aware of regional and resort-specific differences, like how extreme terrain is defined, the use of double or triple symbols, and unique historical designations.

By keeping these factors in mind, you can enjoy safer, more enjoyable days in the mountains.