Review Of The Great Lark 10 UL Sleeping Bag

After five years of owning it, it’s about time I updated this Feathered Friends Lark 10 UL sleeping bag review. With newer versions of the Lark now released, the original Lark 10 UL sleeping bag is discounted, making it a great time to buy if you’ve been eyeing a premium 10°F down sleeping bag. In this review, I’ll share my real-world experience with the Lark 10 UL, why I chose a men’s sleeping bag as a woman, and whether the older model is still worth buying compared to the newer version.

About Feathered Friends

Feathered Friends is a Seattle-based outdoor gear company founded in 1972 and known for its high-quality down insulation and long-lasting craftsmanship. All of their sleeping bags are made in Seattle using premium materials, including 950+ fill power goose down that’s certified under the Responsible Down Standard (RDS).

The brand is especially respected for its attention to detail, ethical sourcing, and use of proven technical fabrics like Pertex®, making their sleeping bags a favorite among backpackers, climbers, and cold sleepers who want gear that lasts for decades, not seasons.

Choosing My Sleeping Bag

Selecting the right sleeping bag was a significant challenge for me. After leaving Europe a decade ago, I parted ways with all my camping gear, expecting to take a break from outdoor adventures for a few years. It wasn’t until 2020, after completing my higher education, that I regained the freedom to set out and acquire new gear. However, this process proved far from straightforward.

The Challenges of 2020

We all remember what happened in 2020 – COVID-19 made in-store testing of sleeping bags impossible, and limited stock further complicated my decision-making. It was during this time that I discovered Feathered Friends, a company whose values resonated with me. The glowing reviews on their website only heightened my interest. Feathered Friends offers an impressive range of over 35 down sleeping bag models designed for adventures in temperatures ranging from 40ºF (4ºC) to -60ºF (-51ºC)!

Searching for the Perfect Feathered Friends Sleeping Bag

At the time, the sleeping bags I was interested in were not available in the colors I wanted or in the size I needed. And because of the price, I didn’t want to compromise on any aspect. So I set up a notification for the Egret 20UL, Petrel 10UL, Lark 10UL, and Hummingbird 20UL, and let fate choose for me.

These sleeping bags were hot commodities in 2020, and you had to act fast when the notification came that one was available. After missing out on a couple of other bags, and despite the hurdles and the uncertainty, I finally managed to catch a Feathered Friends Lark 10 UL sleeping bag! To my delight, the decision paid off, and I am thoroughly pleased with my choice.

Five years on, am I still happy with my choice?

While I sometimes consider opting for a women’s sleeping bag like the Egret 20 UL for its slightly lighter weight, I find that the Lark 10 UL offers the flexibility I need, especially when paired with the summer bag for colder nights. It strikes the perfect balance for my adventures, providing warmth on chilly nights without feeling too hot during the summer. The weight difference between the Lark 10 UL and the Egret 20 UL is just 4 oz, and with my summer bag adding only 8 oz, the total weight remains manageable, allowing me to stay adaptable for a variety of conditions.

Read on for a detailed review of the Feathered Friends Lark 10 UL, including its features, pros and cons, and how it stacks up against other options for your outdoor adventures.

Feathered Friends’ Ultralight Sleeping Bag Options

Feathered Friends’ ultralight sleeping bags are meticulously crafted with Pertex® Endurance® UL fabric, ensuring durability without compromising on weight. The use of 15-denier ripstop nylon adds extra resilience to these lightweight designs.

Superior Insulation

Feathered Friends sleeping bags feature 950+ Goose Down insulation, providing optimal warmth across a wide range of environmental conditions. This high-quality insulation makes them ideal for various outdoor adventures.

Made in the USA

Proudly made in Seattle, USA, with imported materials, these sleeping bags reflect a dedication to quality craftsmanship and local manufacturing standards.

Customized Fit Options

Feathered Friends offers various sleeping bag options, including multiple shoulder-width choices. This flexibility caters to individuals with different body builds, ensuring a comfortable fit tailored to each user’s unique needs.

Additionally, custom fill weight and custom orders are available, providing even greater personalization to match your specific preferences and outdoor requirements.

How to Choose the Best Feathered Friends Sleeping Bag

To help you find the perfect fit, Feathered Friends provides a comprehensive guide on their website, including a comparative table of sleeping bag shapes and dimensions. These details, including shoulder and hip measurements along with height recommendations, ensure you can choose a bag that accommodates your build comfortably. You can also refer to the table below for these specifications by bag size:

• Under 5’9″ (small and medium): Egret, Petrel
• Over 5’9″ (regular and long): Hummingbird, Swallow, Lark, Swift, Raven, Spoonbill

FF Sleeping Bag Comparative Table

Sleeping Bag Name	Dimensions	Temp Rating	Average Weight	Packed Size
Egret UL 20 Women’s	54″ shoulder 56″ hip 38″ footbox	20ºF / -6.67ºC	Small 1 lb 9.6 oz / 726 g Med 1 lb 11.2 oz / 771 g	9L
Egret UL 30 Women’s	54″ shoulder 56″ hip 38″ footbox	30ºF / -1.1ºC	Small 1 lb 7.5 oz / 667 g Med 1 lb 8.8 oz / 704 g	8L
Petrel 10 UL Women’s	54″ shoulder 56″ hip 38″ footbox	10ºF / -12.2ºC	Small 1 lb 14.2 oz / 857 g Med 2 lb 0.3 oz / 916 g	11L
Hummingbird UL 20	58″ shoulder 52″ hip 38″ footbox	20ºF / -6.67ºC	Reg 1 lb 8 oz / 680 g Long 1 lb 9.4 oz / 720 g	9L
Hummingbird UL 30	58″ shoulder 52″ hip 38″ footbox	30ºF / -1.1ºC	Reg 1 lb 5.4 oz / 606 g Long 1 lb 6.4 oz / 635 g	8L
Swallow UL 20	60″ shoulder 56″ hip 38″ footbox	20ºF / -6.67ºC	Reg 1 lb 11 oz / 766 g Long 1 lb 12.5 oz / 808 g	9L
Swallow UL 30	60″ shoulder 56″ hip 38″ footbox	30ºF / -1.1ºC	Reg 1 lb 9 oz / 710 g Long 1 lb 10.2 oz / 744 g	8L
Lark 10 UL	60″ shoulder 56″ hip 38″ footbox	10ºF / -12.2ºC	Reg 1 lb 15.3 oz / 887 g Long 2 lb 1.1 oz / 938 g	11L
Swift UL 20	64″ shoulder 58″ hip 40″ footbox	20ºF / -6.67ºC	Reg 1 lb 13.2 oz / 829 g Long 1 lb 15.1 oz / 881 g	9L
Swift UL 30	64″ shoulder 58″ hip 40″ footbox	30ºF / -1.1ºC	Reg 1 lb 11.2 oz / 771 g Long 1 lb 12.6 oz / 812 g	9L
Raven 10 UL	64″ shoulder 58″ hip 40″ footbox	10ºF / -12.2ºC	Reg 2 lb 2.6 oz / 980 g Long 2 lb 5 oz / 1,050 g	11L
Spoonbill UL 2 Person	104″ shoulder 90″ hip 68″ footbox	Not Rated	Reg 2 lb 6.3 oz / 1086 g Long 2 lb 8 oz / 1136 g	17L (7″ x 14″)

Feathered Friends Lark 10 UL Sleeping Bag Review

Why I Chose a Men’s Sleeping Bag (and Who This Review Is For)

Although the Lark 10 UL is technically a men’s sleeping bag, I chose it intentionally. At 5’10”, I wanted extra length, more shoulder room, and the ability to move comfortably while sleeping, especially on longer trips.

This review will be most helpful if you:

• Are taller than average
• Prefer a roomier mummy bag
• Move around or side-sleep
• Are deciding between a women’s-specific bag and a standard/men’s fit

If you’re smaller-framed or prioritize the lightest possible setup, a women’s model like the Egret may be a better match. But if comfort, versatility, and space matter more to you than shaving every last ounce, the Lark 10 UL is absolutely worth considering.

Lark 10 UL: Versatile Warmth for Changing Conditions

When I’m backpacking, and temperatures dip into the low 30s°F (around 0°C) and below, I layer a lightweight summer bag inside the Lark 10 UL to boost warmth. This setup has kept me comfortably warm even when overnight temperatures dropped below freezing (below 0°C).

The added weight is only about 8 oz (227 g), making it a practical way to extend the Lark’s range on colder backpacking trips without committing to a heavier winter bag.

Handling Sub-Freezing Conditions with the Lark 10 UL Sleeping Bag

When I’m car camping in winter, and temperatures drop below freezing, I add a tent comforter over the top of the Lark 10 UL. This creates a warm cocoon and makes a huge difference on cold nights. Even when I wake up to snow outside the tent, I stay cozy and warm all night.

This setup adds about 1 lb 15 oz of extra weight, but since I’m car camping in these conditions, the trade-off is well worth it for the warmth and comfort.

Weighing the Trade-Offs: Lark 10 UL vs. Other Sleeping Bags

While a snugger-fitting women’s sleeping bag would weigh less and offer similar warmth, how often do I actually encounter sub-freezing temperatures on a backpacking trip? Not frequently. When it’s that cold, I’m typically car camping, where the car is nearby to carry the extra weight.

Plus, at 178 cm (5’10”), I don’t want to feel constricted in a bag that might be too short for me. Women’s sleeping bags also lack the extra space I need to store electronics, water filters, and other items that can’t freeze while I sleep.

Comfort and Flexibility for All Seasons

What I adore about my setup is its flexibility, allowing me to comfortably sleep outdoors year-round. I’ve woken up on sub-freezing nights in a frozen landscape, yet remained snug and warm throughout. The Lark sleeping bag has never failed me, and my love for it grows with each adventure. It’s the perfect blend of comfort and adaptability for all seasons.

Consider Your Typical Conditions

It’s essential to consider the temperatures you’ll experience most often. For example, I frequent desert trips, where winters can be much colder than summer in the mountains. In the desert, temperatures can plummet at night, even when it’s warm during the day, while the mountains might be cooler but still manageable in the summer. This is why my current setup works well for me, but it might not be the best fit for everyone. If you’re primarily camping in warmer weather or during summer months in the mountains, a lighter bag might suit your needs better. Always take the specific temperature ranges of your most common destinations into account when selecting your sleeping bag.

Understanding Sleeping Bag Ratings

Keep in mind that sleeping bags are rated to keep you alive at their lowest temperature rating, but that doesn’t always mean they will keep you comfortably warm. The rating is based on the minimum temperature the bag will protect you from the elements, preventing hypothermia or frostbite. However, for optimal warmth, you might want to choose a sleeping bag with a slightly higher comfort rating, especially if you plan to sleep soundly in cold conditions. Always consider the conditions you’ll face and whether you’ll need extra layers or insulation to stay comfortable.

Premium Quality and Thoughtful Features on the Lark 10 UL

The palpable quality of the Pertex® Endurance UL fabric in my Feathered Friends Lark 10 UL Sleeping Bag is one of the reasons I adore it. The feather-light construction adds to the overall appeal, ensuring easy portability without compromising on performance.

What truly sets it apart is the full collar that wraps around my neck, providing a comforting hug, and the adjustable cords that allow me to tailor the fit snugger around my head. These thoughtful features contribute to the exceptional comfort and adaptability that make my sleeping bag a cherished companion on every outdoor adventure.

Lark 10 UL Sleeping Bag Specifications

The Feathered Friends Lark 10 UL sleeping bag is a mummy-shaped design with a #5 YKK two-way zipper featuring locking sliders. It includes a full collar for effective heat retention, a trapezoidal foot box for natural foot positioning, and continuous baffles for customizable insulation placement. The 3D contoured hood adjusts for varying temperatures, and a generous draft tube prevents cold air infiltration. The bag comes with a storage bag and a stuff sack.

Ideal Sleeper Height	Reg: 6′ 0″ / 183 cm Long: 6′ 6″ / 198 cm
Dimensions	60″ shoulder / 56″ hip / 38″ footbox
Zipper	Left Side, YKK #5
Shell	Pertex® Endurance UL
Lining	Flite 15 denier ripstop nylon
Fill Power	950+ Goose Down
Origin	Made in Seattle, USA of imported materials
Temp Rating	10ºF / -12.2ºC
Fill Weight	Reg: 1 lb 4 oz / 568 g Long: 1 lb 5.2 oz / 602 g
Average Weight	Reg: 1 lb 15.3 oz / 887 g Long: 2 lb 1.1 oz / 938 g
Packed Size	11L

In-Depth Look at the Features of the Lark 10 UL Sleeping Bag

The Lark sleeping bag offers a combination of features that make it a versatile and reliable choice for outdoor enthusiasts. Here are the key attributes that set it apart:

• Ultralight Construction: Crafted with Pertex® Endurance® 10 denier water-resistant/breathable fabric, this sleeping bag strikes a perfect balance between weight and performance, ensuring that it won’t weigh you down on your adventures.
• Mummy Shape: With an average width, it offers a snug yet comfortable fit that allows for movement while keeping you warm.
• Full Collar: The full collar creates an effective seal around your neck, trapping heat and ensuring a cozy night’s sleep.
• Trapezoidal Footbox: This innovative design allows your feet to rest naturally, without compressing the sides, enhancing overall comfort.
• Continuous Baffles: The continuous baffles permit you to adjust the insulation to your liking, tailoring warmth to your specific needs.
• 3D Contoured Hood: The hood opens wide for warm nights and cinches tight when temperatures drop, providing adaptable comfort.
• Generous Draft Tube: A well-thought-out draft tube prevents cold air from seeping past the zipper, maintaining a warm interior.
• Convenient Accessories: The sleeping bag comes with a storage bag and stuff sack, making it easy to pack and store.

Sizing Options: The Lark 10 UL is available in two sizes to accommodate campers of varying heights:

• Regular Length: Suitable for individuals up to 6′ 0″ | 183 cm.
• Long Length: Ideal for those up to 6′ 6″ | 198 cm.

Is the Lark 10 UL the Best Feathered Friends Sleeping Bag?

The “best” sleeping bag from Feathered Friends really depends on how and where you camp, but for me, the Lark 10 UL hits the best overall balance of warmth, space, and versatility.

Compared to narrower bags like the Egret or Petrel, the Lark offers more room to move, which matters if you’re a side sleeper or tend to shift positions at night. Wider options like the Swift or Raven provide even more space, but they come with a weight penalty that I don’t always want for backpacking.

If you want a true 10°F bag that works for three-season backpacking, shoulder-season trips, and even light winter use, without feeling overly restrictive, the Lark 10 UL is one of the most well-rounded Feathered Friends sleeping bags available.

Old vs New Lark 10 UL: What to Know Before You Buy

Feathered Friends released an updated version of the Lark 10 UL in Fall 2025. Because of this, the previous Lark 10 UL model is now discounted.

Both versions have the same 10°F temperature rating, use 950+ fill power down, and share the same fit, dimensions, and overall warmth.

The newer version adds updated shell fabrics, a more durable footbox lining, and small sustainability improvements. These changes do not affect warmth or comfort.

If you can find the older Lark 10 UL on sale, it is still an excellent buy and offers better value for most people. The new version makes sense if you want tougher fabrics or the newest materials.

Feature	Previous Lark 10 UL	New Lark 10 UL (Fall 2025)
Temp Rating	10°F / -12.2°C	10°F / -12.2°C
Fill Power	950+ goose down	950+ goose down
Average Weight (Reg)	1 lb 15.3 oz	1 lb 14.9 oz
Packed Size	11L	11L
Shell Fabric	Pertex Endurance UL (10D)	Pertex Quantum Pro
Footbox	Standard UL fabric	Diamond Fuse lining
DWR	Standard	PFAS-free
Sustainability	RDS down	RDS + recycled fabrics
Fit & Dimensions	Same	Same

Feathered Friends Lark 10 UL: Pros and Cons

Based on my experience, here’s an overview of the pros and cons of the Feathered Friends Lark 10 UL Sleeping Bag:

FAQ About the Feathered Friends Lark 10 UL Sleeping Bag

Is the Lark 10 UL warm enough for winter camping?
Yes, it’s rated to 10ºF / -12.2ºC and performs well in sub-freezing conditions. With layering (like adding a summer bag inside or using a tent quilt), it can handle colder temperatures comfortably.

How much does the Lark 10 UL sleeping bag weigh?
The regular size weighs 1 lb 15.3 oz (887 g), and the long size weighs 2 lb 1.1 oz (938 g), making it ultralight for a cold-weather bag.

Does it pack down small?
Yes, the packed size is 11L. While not the most compact ultralight bag, it’s a great balance of warmth, weight, and packability for three-season to light winter use.

Is the Lark 10 UL good for people who move around in their sleep?
Definitely! With a 60″ shoulder width, it’s one of the roomiest mummy bags in its category, offering excellent mobility and comfort for side sleepers or those who shift positions often.

What fabric does Feathered Friends use in the Lark 10 UL?
It uses Pertex® Endurance® UL for the shell and Flite 15 denier ripstop nylon for the lining, lightweight, durable, and weather-resistant materials trusted by serious outdoor adventurers.

Where is the Lark 10 UL made?
All Feathered Friends sleeping bags, including the Lark 10 UL, are proudly made in Seattle, USA, with imported materials.

Can I customize my sleeping bag?
Yes! Feathered Friends offers custom options, including extra fill for specific areas. If you need more insulation in certain panels (like the back), you can request that at the time of order.

Does Feathered Friends offer a warranty?
Yes, they offer a lifetime warranty on their sleeping bags, one of the reasons their gear has such a strong reputation for quality and durability.

Would you buy the Lark 10 UL again?
Absolutely. After five years, I still love this sleeping bag. While I might request extra fill next time, it’s proven itself on countless trips in various conditions and remains a staple in my gear closet.

Who is the Feathered Friends Lark 10 UL Is Best For?
The Lark 10 UL is a great choice if you:

• Want a true 10°F (-12°C) sleeping bag without extreme bulk
• Prefer a roomier mummy bag or move around at night
• Camp across multiple seasons and conditions
• Are deciding between value (older model on sale) vs the newest version

If you mostly camp in warm summer conditions or want the lightest possible setup, a higher-temperature or women’s-specific model may be a better fit.

Final Thoughts on the Lark 10 UL Sleeping Bag

My experience with the Feathered Friends Lark 10 UL Sleeping Bag has been nothing short of exceptional. Its roomy design, reliable warmth, and adaptability to various weather conditions have allowed me to enjoy camping and backpacking year-round fully. Whether you’re facing chilly spring evenings or sub-freezing winter nights, this sleeping bag offers comfort, versatility, and reliable warmth.

With Feathered Friends, I’ve discovered a trusty companion that ensures I can embrace the elements and create unforgettable memories in the great outdoors. If you’re ready to elevate your outdoor experience with a sleeping bag that provides the perfect blend of space, comfort, and warmth, the Lark sleeping bag is a fantastic choice.

Post originally published on January 16, 2024, and last updated on December 21, 2025.