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ALPS Mountaineering Crescent Lake 20

rated 4.5 of 5 stars
photo: ALPS Mountaineering Crescent Lake 20 3-season synthetic sleeping bag

The ALPS Mountaineering Crescent Lake +20F sleeping bag is warm and comfortable, relatively roomy, and retains its loft very well. It's one of the few sleeping bags I've ever used with an accurate temperature rating.


  • Comfort
  • Warmth
  • Length
  • Roomy footbox
  • Roomy enough to sleep on my side


  • Could be a little more roomy in the shoulder area for easy zipping
  • Top portion of draft collar doesn't drape very well
  • Zipper snags easily
  • Face opening is hard to close due to odd shape

I picked up this sleeping bag in late spring, but it was too warm to use until just about a month ago. In that time I've used it maybe 15 nights, in temps ranging from around 40°F to 16-18°F, and am pretty impressed with it. I like it enough that I bought an ALPS Mountaineering Echo Lake -20F sleeping bag for winter used based solely on my impressions of this one. I'm looking forward to trying that one out soon!

I bought the wide bag. I don't have the measurements handy but suffice it to say I'm 5'11" and 275 lbs and sleep quite comfortably in it. I wouldn't mind it being a little wider, but I need to become a little less wide myself LOL.

Strangely enough, it fits better when I sleep on my side than on my back. I prefer to sleep on my back, though, but usually wake up to roll on my side for a while 2 or 3 times a night. The length is fine. I'd guess someone up to 6'2" would be comfortable in it based on how much extra room I have. There's a draft collar that goes all around and secures with Velcro. It has a drawstring to let you snug it around your neck.

I think what impressed me most about this bag was its warmth. I remember thinking that I'd have to use a liner or my woobie once the temp hit around 30, but at that temp I was overheated with merino top and bottom and wool socks. I ended up opening the bottom zip about halfway and leaving the top zip undone about a foot, using the Velcro flap to keep it closed around my neck.

Down to around 26 degrees I stayed warm all night in just a pair of shorts. When temps dropped below 20°F I wore the merino top and bottom, no socks, and a lightweight hood, more to keep hair oil from soiling the bag than for warmth. I ended up with my head outside the bag because I was too warm with it inside.

In temps over 40°F I'd need to use a lighter weight bag, so I'd call it a 2-season bag (spring and fall.) I'm typically a very warm sleeper, though.

In all cases I was in my Jagged Peak 2 tent, with the rain fly on and at least the roof vents open. I ended up having to open both end windows and 1 of the doors to keep from overheating even below 20°F. One night there was a surprise rain shower and the part of the sleeping bag that was under the door screen got wet, but no water made it through. 

As I said before, it could stand a little more room in the shoulder area. I don't find it uncomfortable, but it's difficult to hold the zipper halves close together while zipping it up from the inside. I end up having to roll on my side and stick one arm outside the sleeping bag to zip, while my other hand pulls the draft tube back from the zipper on the inside. The little bend in the zipper as it nears the top is the hardest part. 

And while I'm talking about the zipper, it does have a tendency to snag since there's no backing behind it. Just pull the zipper back and the fabric pops out, with no tears as of yet. 

The draft collar is an oblong fabric tube about 5" wide, that runs above and below you. It does an OK job but there are limitations based on its shape. I'd rather see a wide horseshoe or yoke shaped collar with maybe a 6" gap between the legs, which seems like it'd fill the gap much better. 

Lastly, the face opening is oblong and runs from side to side, so closing it enough to keep cold air from getting in on the sides pretty much closes it up completely. I don't like sleeping with my face covered, which is why I usually sleep with my head outside the bag.

This is no high-end lightweight backpacking bag, although it's not so heavy or bulky that you couldn't use it that way. But I think you'd have a hard time beating it for car camping. I'll be toting either this one or my Echo Lake on a sled this winter.

Source: bought it new
Price Paid: $45

It's soft because it's bulky, but man is it bulky.


  • Warm
  • Soft
  • Maintains loft well


  • Doesn't pack well
  • Head doesn't tighten well
  • Little heavy for backpacking



I've had this sleeping bag for about a year, and it's the only one I've backpacked with since then. The reviews I had read suggested it was best for backpacking, but I think it is better for car camping.

It's warm and has kept me warm in 28 degree nights in Tennessee. The regular size fits my 5'8" frame rather well, although sometimes there is too much room for cold air at my feet. Getting in and out of the bag is easy, and the zippers are insulated well. Any condensation dries quickly in the morning, and the loft is maintained well.

The bag has two drawstrings in the hood, one for the hood and one for a draft collar around the neck. This draft collar is excellent for keeping the rest of the body warm. My feet get cold at times, and I haven't figured out if I'm pushing my feet against the foot of the tent or something, but the warmth generated from tightening the draft collar seems to help move warm air down to my feet.

The bag is soft, making me enjoy sleeping on a lower quality sleeping pad a little bit more. I wish it had a pocket inside it for a phone or other small item.

The big problem to me is its packability. It's 3.5 pounds, which is not awful for a synthetic bag. But it doesn't pack down very small. It feels like it takes up half of my 50 liter pack. It's bigger than a basketball.

The price is great, really great. And I do believe it's warmer than some other bags such as The North Face Furnace 20. But I'd rather have the Furnace because it packs down better. I feel like the size of this bag causes me to go lighter on other gear on trips, and I don't like that feeling.

I intend to get a different bag soon.

Source: bought it new
Price Paid: $50

I needed a second mummy bag so I decided on the ALPS Crescent Lake seeing I purchased my Silver Springs from them three years ago and I know from experience that ALPS Mountaineering's products are very good.

The Weather Channel was predicting a cold front was going to push through Saturday night and drop the nighttime temps down to the low thirties so I decided to put my Crescent Lake to the test.

The first thing I did was see how the fit was. I did this prior to taking it camping. As with my other ALPS bag, the fit was right on and the contoured hood was very comfortable and was a very nice feature I appreciated that night when the temps took that big plunge! This bag has a puffy zipper draft tube that kept cold air from creeping in but it did lack a draft tube for the chest, unlike my Silver Springs. But I noticed hardly any cold air creeping in even though it lacked this feature. Seeing I got last year's model this particuliar bag had PolyMAX instead of this year's TechLoft, which I suppose is the same insulation since it has the same construction (a hollow polyester fiber not unlike Dupont's Hollofil 808). I was very warm in this bag. The hood worked great, the fit is excellent and I'm very pleased with my purchase! This bag is a definite great buy that works well even when those temperatures take that big drop! The bag is rated to 20 degrees. I highly recommend it!

Update: January 10, 2006

This is one excellent bag. It is true to its temperature rating. I've been using it this past week for cold weather camping. I haven't had a cold night yet.

The design and materials of this bag are excellent. It sports one of the BEST hood designs I found. Pull the drawstrings and the hood totally surrounds your head and traps in the precious body heat. The polyester taffeta outer shell/inner liner is plan just soft and very comfortable. The material is very hydrophobic--it will not retain any moisture for long. The bag has a full length zipper baffle but no chest baffles. Yet I haven't had any cold air creep in.

This year's model uses ALPS Mountaineering's proprietary Tech Loft, which is a four channel siliconized hollow fiber much like DuPont's Hollofil II. For the price, materials and performance, I will recommend this excellent bag from ALPS Mountaineering.

Design: mummy
Fill: Tech Loft
Temperature Rating: 20 Degrees Farenheight
Weight: 4lbs 6ozs
Price Paid: $49.99

Needed to buy my son some camping gear for Scouts and decided to splurge on a new bag for myself. Bought the Crescent Lake Long since I like extra room in my bag given my 250lb 6' frame.

First, use was during a winter camping trip in the Los Padres. Overnight temps got down to the teens. Bag felt warm and comfortable and the easy drawstring hood came in handy. Both nights slept very warm and second morning woke up with frost around the hood so I know it was cold. No question it stood up to the test for cold.

Second use was a winter camping trip to Yosemite. Overnight temps in the 20's. Given the light weight it was an easy backpack in. Unfortunately I had a mattress failure so I had little insulation between myself and the snow. My body did stay warm, but I could feel the cold against my back and did make it a bit uncomfortable. I would not blame this on the bag as you should always use an insulated ground pad for winter camping.

Third Use was an overnighter where we slept under a rain fly. Overnight temps in the 40's. Again the bag was comfortable.

Fourth use was warmer spring night. Overnight temps in the 50's. Slept in a hammock. Bag was very comfortable and not overly warm.

Overall: I am very impressed with the bag. The draft tubes keep out the cool air effectively and create a snuggly sleeping environment. The hood worked brilliantly in the cold and was easy to open and close. The stuff sack that comes with the bag has four drawcords and can pack the bag down to less than a ft^2 and can easily fit into an internal frame pack sleeping bag pocket with a lot of room to spare for a pillow or a ground pad.

My son (11) has been with me on every trip and has the smaller Crescent Lake 20 regular. He has not complained of cold either. Both of us are very satisfied customers.

The only issue I have with the bag is the zipper gets caught on the draft tube fabric and can be frustrating at times. This is minor considering the functionality of the bag in multiple conditions.

Design: Mummy long
Fill: 210T Polyester
Temperature Rating: 20
Weight: 4 lb. 6 oz. (Long) /3 lb. 12 oz. (Regular)

All things considered... 5 stars.


  • Well designed
  • Generous fit
  • High loft
  • Comfort

For the price, the Alps Crescent Lake is a very good bag. The dimensions are generous compared to the sizing of most mummy bags. The amount of loft surprised me. It's thick! Of course this comes at the expense of weight and pack size. 3lbs12oz for the "regular". 

I use the Alps for car camping to keep miles off my backpacking bags. The Crescent Lake will fit into the sleeping bag compartment of external frame Kelty packs, but it's too big for the bag compartment of most internal frames. 

I've got a good 60 nights in this bag. I've used it in 40°F-65°F nights and was neither cold nor sweating. I only compress it while traveling and store it in a large plastic storage bin at home. It's wearing well and still looks brand new. Not a huge issue, but I like the colors. It doesn't look like a bag of skittles.

Did get the zipper hung up once, but was able to get it undone. Helps that there is a second zipper pull on the bottom so it can be unzipped from both directions.

Considering performance, design, comfort, and price... this is a great product.

Source: bought it new
Price Paid: $55

I was very pleased with this purchase. The design of the bag is great. I am about 6'0" 185, and I *hate* the constriction of mummy bags. But I slept as comfortably in this bag as in any bag I've slept in. The zipper and hood design were good and I was very warm in this bag nights in the mid 30s, which indicates to me that it's fairly true to its rating, unlike some other brands.

It's very light and stuffs quite small. I have no complaints with this bag, the price was great, and I will probably purchase other Alps Mountaineering products.

Design: Mummy
Fill: proprietary synthetic
Temperature Rating: 20 F
Weight: 3+ lbs (?)
Price Paid: $45

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Price $79.99 USD $89.99 USD $89.99 USD
Product Details from ALPS Mountaineering »