Teton Sports Altos Ultralight Down Mummy Sleeping Bag: Perfect for Sleeping in Freezing Temperatures

Teton Sports Altos dimensions
Jerry Mueller
Written by Jerry Mueller

When camping, your sleeping bag becomes your best friend. While many individuals may consider tents the most important camping gear to bring along, ultimately a tent isn’t responsible for keeping you warm throughout the night. While a tent will protect individuals from rain, wind, and other weather elements, it’s a sleeping bag that provides actual warmth and comfort. Therefore, having a reliable sleeping bag is just as important as having a reliable tent.

A sleeping bag’s purpose is to provide you with warmth, comfort, and a good night’s sleep. For those looking for durable, comfortable, year-round sleeping bag the Teton Sports Altos Ultralight Down Mummy Sleeping Bag is a great option to consider.

Product Specifications

  • Water-resistance down mummy bag
  • Roomy sleeping bag
  • Backpacker’s dream bag – unrivaled warmth of down that will dry out quickly if it gets wet
  • High-quality construction – tough ripstop shell for rugged conditions
  • 3 piece hood contours your face to keep your whole head warm
  • Vaulted foot box
  • Anti-snag zipper with a full-length zipper draft tube eliminates any cold spots

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Unlike many mummy sleeping bags, the Teton Down Mummy Sleeping Bag is not available in different sizes. However, even though they are all the same length there are still three different versions available, each one able to handle different temperatures. Therefore, this sleeping bag is perfect for individuals who camp during the winter or in the mountains when it can get extremely cold. The warmest of the three variations can keep individuals warm in temperatures as low as -10°F.

Teton Sports Altos durability

Furthermore, the Teton Mummy Sleeping Bags has a number of features and qualities that make it an attractive option for many individuals. It is made from ripstop nylon, an incredibly durable material that is water and tear resistant. When cared for properly, this sleeping bag has the potential to be a reliable companion for many years, making it a great investment.

Since this sleeping bag can handle colder weather is can be used anywhere. While it is a bit on the heavier side, it’s comfortable and won’t let you down. It is built extremely well and provides you with all the tools to get a good night’s sleep to feel refreshed and ready to hike the next morning.

Best Use: When This Sleeping Bag Is Most Effective

The Teton Down Mummy Sleeping Bag is an incredibly versatile sleeping bag, making it perfect for any camping or hiking trip. If you purchase the 0° or -10° sleeping bag, it may get a little warm during the summer. However, it is still a great option for year-round camping. It can be used in any kind of weather and on any kind of terrain.

It is difficult to find a sleeping bag that can meet every point on your checklist. Fortunately, the Teton Down Mummy Sleeping Bag does. It is warm, comfortable, water resistant, fairly priced, and durable.


Each version of the Teton Down Mummy Sleeping Bag becomes fairly compact when it is packed into the stuff sack. The 20°F bag compresses down to 14 x 8 x 8 inches; the 0°F bag compresses down to 15.5 x 9 x 9 inches, and the -10°F bag compresses down to 16.5 x 10 x 10 inches.

The 20° bag is the smallest because it contains the least amount of down. However, even the warmest version is no taller than 2 feet and no wider than 1 foot.

Furthermore, each stuff sack has cinch strips and buckles attached to it. When these buckles and straps are pulled as tight as they can go, without risk of them ripping, the bag can be compressed even more. Therefore, each compressed bag should fit comfortably in any backpack of varying sizes.

Overall, for being 4-season sleeping bags they don’t take up a lot of room, which is nice when you have to try and fit a bunch of camping gear into one bag.

Design And Durability

Teton Mummy Sleeping Bags look similar to mummy sleeping bags sold by other manufacturers. It is wider near the shoulders and narrower near the feet. Like all mummy sleeping bags, it is designed to follow the shape of the body, which can help individuals stay warmer on colder nights. However, there are several features that make this sleeping bag stand out from the rest.

Teton Sports Altos design internal

On the left side of the sleeping bag there is a full-length zipper baffle and draft tube. This makes it easy to get in and out of the sleeping bag, as well as helps keep the heat from escaping during the night.

The bag includes a 3-piece, ultra-puff hood, which can be adjusted to comfortably form around the face and head. The down is hydrophobic MTN-DRY duck down, which is more resistant to water than traditional down. It also dries quicker than traditional down, meaning it will maintain loftness better. Furthermore, the bag includes a pocket on the inside that can be used to store small objects, such as a phone or wallet.

Not only is this sleeping bag comfortable and convenient, but it is durable and reliable. The shell of the bag is made from 20-denier, diamond ripstop and the lining is made from 20-denier nylon fabric. Ripstop and nylon fabrics are known for their durability. They are typically tear resistant, water resistant, and wind resistant. Therefore, this sleeping bag should last many years unless natural wear and tear or improper care causes it to become damaged.

Overall, the Teton Mummy Sleeping Bag has an incredible reputation. Unlike some other sleeping bags, there are no reports pertaining to manufacturer defects or a lack of warmth while sleeping. There are some complaints that the down has a slight smell to it, but the smell fades as the more it is used and aired out.


Despite being advertised as “ultralight,” these sleeping bags aren’t the lightest bags on the market. However, they can still be considered lightweight 4-season sleeping bags.

Teton Sports Altos lightweight

The 20° bag weighs 2.5 pounds and is the lightest of the three available. The 0° bag weighs 3.45 pounds and the -10° bag weighs 4.2 pounds. While the warmest bag is on the heavier side, and probably won’t be considered lightweight by many potential customers, it provides the most protection against the cold.

Luckily, the two additional options are lighter, giving potential customers the ability to really think about what they need from their sleeping bag. For individuals who are going to be backpacking in freezing temperatures, the extra weight will be worth it. However, for individuals who will be camping in warmer climates have the ability to purchase a lighter sleeping bag.


Finding a sleeping bag that will keep you warm at night is probably at the top of your list. If it isn’t at the top of your list, then it’s probably pretty close. No one wants to settle down for the night and find themselves shivering because of the cold. Being cold is uncomfortable and makes it difficult to get a decent night’s sleep. It can really throw off the success, and pace, of your hiking trip.

The Teton Mummy Sleeping Bag warmth rating is difficult to beat. The warmest of the three versions will keep individuals warm in temperatures 10° below 0. Therefore, the -10° sleeping bag is a great choice for individuals who mountain climb, or hike in the middle of winter when temperatures can become extremely cold. However, the other two sleeping bags are still good options for hiking and camping year-round.

The 0° sleeping bag will keep individuals warm in temperatures above 0°F and the 20° sleeping bag will keep individuals warm in temperatures above 20°F. Therefore, even the sleeping bag with the lowest warmth rating will still keep you warm in a variety of climates.

There have been a few complaints regarding the smell of the down. However, if the down does have a slight smell to it, air it out and it should go away quickly. More than likely the smell is a result of being packed up for an extended period of time.


The more comfortable a sleeping bag makes individuals feel, the better they will sleep. Mummy sleeping bags usually have a tighter fit than other sleeping bags. Despite being designed to have a snug fit to keep individuals warmer during the night, sleeping in a mummy sleeping bag shouldn’t make you feel claustrophobic. You still want to have room to move around when you need to.

Teton Sports Altos Dimensions

Each version of the Teton Mummy Sleeping Bag is the same size. They are 84 inches long, 32 inches wide near the shoulders, and 17 inches wide near the feet. While smaller individuals may find this sleeping bag a bit big, taller and larger individuals will find that they have plenty of room after they zip themselves into it.

The Teton Mummy Sleeping Bag is on the larger size, which is a positive selling point for many customers. Individuals feel warm and roomy in this sleeping bag, which can be a difficult combination to find sometimes.


Having a comfortable sleeping bag is just as important as having a warm sleeping bag. While many individuals bring along sleeping pads for extra protection against the hard ground, as sleeping bag still needs to offer a certain degree of comfortability. Otherwise, it will be hard to ignore the fact you are sleeping on the ground instead of in your bed at home.

The Teton Mummy Sleeping Bag forms to the body better than other mummy sleeping bags. While the main part of the bag is known for being roomy, the area that holds the head has a reputation for being extremely comfortable.

The area around the head is a 3-piece, ultra-poof hood. The hood offers plenty of padding, that forms around your head comfortability, keeping heat trapped inside the bag.

Overall, these sleeping bags have a reputation for being more comfortable than other sleeping bags.

Weather Resistant

Having a weather resistant sleeping bag is just as important as having a weather resistant tent. Tents can develop leaks or tear unexpectedly. Condensation can also build up inside the tent. Therefore, your sleeping bag needs to be able to protect you from the elements to some degree. Most importantly, it needs to be able to keep you dry when water does find its way into the tent.

Fortunately, the Teton Sleeping Bag’s diamond ripstop shell is water resistant. Therefore, it will keep you dry even when water does manage to find its way into the tent. The water-resistant seal will also help protect the down from becoming wet, which will help the down maintain its loft for longer.

Value For Money And Guarantee

The cost for the Teton Mummy Sleeping bag differs. The sleeping bag with the most down is the most expensive. However, it’s expected to pay a bit more for extra warmth. Why don’t you check the promotional video below?

The 20°F sleeping bag costs approximately $160. The 0°F sleeping bag costs approximately $214, and the -10°F sleeping bag costs approximately $290. The prices for each bag are quite a difference; however, each individual sleeping bag is priced well for the materials it uses and the temperatures it can handle.

Most sleeping bags are priced on their length and size. However, the Teton Mummy Sleeping bag is uniquely priced on its ability to keep individuals warm. Therefore, customers are still getting a terrific value for the money they are spending, even if they choose to purchase the sleeping bag that costs $290.

There aren’t any reported problems about this sleeping bag. There are no manufacturer defects, such as faulty zippers that stick or break easily. These sleeping bags effectively keep individuals warms, even when it is freezing outside.

Furthermore, this sleeping bag is comfortable and durable. It makes individuals feel snug and warm, without making them feel like they can’t move around. It’s easy to get in and out of, and it is easy to roll up and pack away.

These sleeping bags also come with a limited lifetime warranty, making the price even more reasonable. Teton will replace sleeping bags that are damaged upon arrival, as well as any sleeping bags that exhibit manufacturer defects in materials and workmanship.

Close Competitors: Similar Products You Might Like

Even though the Teton Mummy Sleeping Bag is a reliable product that comes highly recommended, you still want to take a moment to compare it to related products. Some mummy sleeping bags may come with slightly distinctive features that you may decide you like better. Therefore, take a look at these mummy sleeping bags before making a final decision.

Teton Sports Tracker +5F Ultralight Sleeping BagTeton Sports Tracker 5F Ultralight Sleeping Bag

There isn’t much difference between the Teton Sports Tracker +5F Ultralight Sleeping Bag and the Teton Down Mummy Sleeping Bag. It looks the same, is the same length, weights about the same, and has many of the same features as its counterpart.

For example, it includes the same 3-piece hood, inner pocket, and full-length zipper and draft tube. Furthermore, it is made from the same materials, meaning it has the same durability as its counterpart.

The significant difference between the two sleeping bags is the price. The Ultralight Sleeping bag costs approximately $70, which is almost half the price of the cheapest Teton Down Sleeping Bag. The second biggest difference is the insulation. Instead of down, this sleeping bag uses body-mapping technology and has extra insulation added around the feet.

Considering this sleeping bag keeps individuals warm in colder temperatures, and has the same features and function as its counterparts, at half the cost, it seems like it is the better deal.

However, this sleeping bag has many more negative reviews. There have been more reports about zippers breaking off and feels small. There are also reports claiming that this sleeping bag shouldn’t be used in temperatures lower than 30°F.

Outdoor Vitals 0 Degree Down Sleeping BagOutdoor Vitals 0 Degree Down Sleeping Bag

The Outdoor Vitals 0 Degree Down Sleeping Bag has a similar look and feel as the Teton sleeping bags. However, it does have some key differences that makes it stand out. Unlike the Teton Mummy Bags, this one comes in three sizes. Therefore, it caters to individuals in a different way than the Teton Bags. While the Teton Sleeping Bags cater to the different climates, the Outdoor Vitals Sleeping Bag caters to individual’s varying heights.

When packed away, this sleeping back compresses down to 11 x 8 inches and weighs 2 pounds 3 ounces. While it may not be ultralight, it’s still light and compact. Therefore, it should fit in your backpack comfortably.

It has two drawstrings near the face, instead of one, to draw the sleeping bag in and keep heat trapped inside. It also has hanging hooks, which makes it convenient to store and air out. The materials used to make this sleeping bag are the same materials used to make the Teton Sleeping Bags. Therefore, it is durable and water resistant.

The Outdoor Vitals Sleeping Bag is similarly priced. It costs approximately $180 to $200, depending on the size purchased. Like Teton, Outdoor Vitals also offers a lifetime warranty to their customers. Considering there aren’t many differences between the two sleeping bags it comes down to whether you choose a sleeping bag based on its length or based on its ability to handle freezing temperatures.

Thermodown 15 Degree Down Mummy Sleeping BagThermodown 15 Degree Down Mummy Sleeping Bag

The Thermodown 15 Degree Down Mummy Sleeping Bag is the only 3-season sleeping bag in this article, which sets it apart from its counterparts. Despite being able to handle climates as cold as 15 degrees, its considered to be a 3-season sleeping bag, meaning you shouldn’t use it during the winter or in climates that can reach freezing temperatures.

If you need a 4-season sleeping bag then you should consider one of the other sleeping bags listed above.

Other than being a 3-season sleeping bag, there isn’t much different between this sleeping bag and its counterparts. It comes in two sizes, weighs 2 pounds 14 ounces, and compresses down to 11 x 8 inches. It is made from the same materials as the other sleeping bags; although, it has different zippers. It is slightly cheaper than the other sleeping bags.

It costs approximately $140 to $145, depending on the size purchases. Like the other sleeping bags, it comes with a limited lifetime warranty.


When it comes to the Teton Mummy Down Sleeping Bag, it’s difficult to find anything negative to say about it. It may be a little warm during the summer, due to the fact it is built to withstand colder temperatures. However, creative individuals have found leaving it unzipped and slightly folded open is a good way to stay cool and comfortable even when it is warm during the night. Therefore, this sleeping bag truly is an investment for year-round camping and hiking.

Furthermore, the Teton Sleeping Bag is extremely durable. It is made from ripstop nylon, a common material used to make sleeping bags. It is water and tear resistant, making it unlikely for the bag to tear unexpectedly, which makes it unlikely for the down to peak through and fall out. Overall, the design of this sleeping bag is strong and there have been no complaints about the structure and durability of it.

The only real complaint against this sleeping bag is the smell. When using it for the first time it is possible the down might have a “duck” smell to it. However, air the sleeping bag out before camping and the smell should go away.

Before deciding whether the Teton Mummy Sleeping Bag is the right investment, here is a comprehensive look at its pros and cons.


  • Can Handle Temperatures As Low As -10°F
  • Comfortable
  • Durable
  • Reasonably Priced
  • Limited Lifetime Warranty
  • Compact


  • On The Heavier Side
  • Has A Slight Smell
  • Warm For Summer Months
  • Only One Size

Overall, the Teton Mummy Sleeping Bag is worth considering. While the warmest of the three variations is a bit pricey it can handle climates that most other sleeping bags can’t. Therefore, it is a great option for individuals who are adventurous and want to be able to hike anywhere and everywhere. Even in warmer temperatures, the sleeping can be left unzipped to allow airflow. Since this sleeping bag is so versatile it is a great investment. You’re truly getting your money’s worth when purchasing this sleeping bag.

Furthermore, this sleeping bag is comfortable. It forms to the body, while also leaving enough room to switch sleeping positions without getting tangled up. While smaller individuals may not like that it is only available in one size, taller individuals will appreciate the ability to fit comfortability. The Teton Mummy Sleeping Bag is a great investment, as it will keep your warm and comfortable throughout the entire night for many years.

Teton Sports Altos Ultralight Down Mummy Sleeping Bag
  • Packaging
  • Design And Durability
  • Weight
  • Warmth
  • Dimensions
  • Comfortability
  • Weather Resistant
  • Value For Money And Guarantee


There isn’t much to complain about when it comes to the Teton Sports Altos Ultralight Down Sleeping Bag. It’s a great sleeping bag for year-round camping and hiking. It can be pulled tight around an individual to stay warm during colder nights or it can be left unzipped to say cool during warmer nights. Therefore, this sleeping bag can be used anywhere, making it a great one-time investment.

Comfortability and durability are two important qualities of this sleeping bag. Made from ripstop nylon, this sleeping bag won’t tear easily. Improper care and natural wear and tear are the only serious culprits for deteriorating this bag over time. While it is only available in one size, it is can comfortably fit larger individuals. Furthermore, the 3-piece hood forms to the face and head, keeping individuals comfortable and warm throughout the entire night. While this sleeping bag may have a slight smell when first used, airing it out will quickly solve that problem.

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Teton Sports Altos Ultralight Down Mummy Sleeping Bag: Perfect for Sleeping in Freezing TemperaturesDo you have experience camping with the Teton Mummy Sleeping Bag? Or do you have alternative that is better? Share your thoughts in the comments section below. 


Jerry Mueller

Jerry Mueller

Jerry ‘Boy Scout’ Mueller spends 99% of his time camping or teaching others how to live in the wild. He became an Eagle Scout which is the highest rank attainable in the Boy Scouting division when he was 17 and after that he still lives the scout life. Jerry always plans neatly every trip, takes leadership very seriously and if you listen to his tips and stories, you can learn tons of useful things.