An inexpensive mummy bag with a warm hood, the ALPS Crescent Lake 20 delivers a lot of warmth relative to its weight, not unlike the Kelty Callisto 20 (our Best Buy winner). The Crescent Lake's big puffy hood and insulated neck collar, do a good job sealing in warmth in cold weather.
We found the Crescent Lake 20 cozy and warm in freezing weather. It is the warmer of the two mummy bags we tested.
The Crescent Lake 20 comes closer to delivering on the manufacturer suggested temperature rating than many other bags. This mummy style bag has two layers of synthetic insulation, the outer one sewn to the polyester shell, and the inner layer sewn to the taffeta lining. This offset-quilting technique is warmer than sewn-through construction. This bag has both a large insulated draft tube to stop cold air along the zipper, and a fat insulated neck collar to seal in warm air. With a top and bottom baselayer on, we got an OK night's sleep in the mid 20s. Around freezing is the more comfortable warm zone though, up through the mid 40s if you leave the neck collar unsecured and your head out of the hood.
A warm draft collar that seals warm air in around your neck is a great feature. If you don't like a hood snugged up around your face, a draft collar allow you to seal in warmth and leave the hood opening loose.
Mummy shaped bags simply couldn't score well in our comfort metric for camping sleeping bags. While the Crescent Lake is roomier than most technical mummy bags for backpacking, it is still much more confining than a rectangular bag. The slippery synthetic lining that saves weight and makes it more water resistant just doesn't feel as nice on bare skin as softer, cotton blend linings. On a positive note, the two-way zipper pulls do allow ventilation at this bag's foot. This is a key feature for venting warm air and extending a mummy bag's useful temperature range upwards.
In addition to the warm draft tube and neck collar, this budget bag includes some features often absent on bargain products. Two large webbing loops for hanging are conveniently sewn into the foot of this bag. The neck collar and zipper securing flaps both fold onto themselves to hide the prickly side of the Velcro when not in use. We found the zipper stiffening tape to work well, though the zipper pull sometimes snagged on the shell fabric. A bargain bag can't have all the nice features, and the cord locks to tighten the draft collar and the hood are not secured to the bag for one handed tightening, instead they're free floating on the cinch strings.
Because the cord lock for adjusting the hood is not sewn into the bag, you'll need two hands to cinch up the hood opening for warmth.
Weighing in at 3 lbs 8 ounces, this bag tied for the lightest we tested. The Bozeman Flame weighs the same. These hooded mummy bags are the optimum shape for getting the most warmth with a minimum of insulation and weight. Packed away in the included stuff sack, the ALPS Crescent Lake 20 is the third smallest bag, both the Bozeman Flame and the Marmot Mavericks 30 are smaller in size.
Fairly compact for it's warmth, a compression sack could create a small packed size if you want to backpack it in to the backcountry.
This bag is a great crossover product if you want a budget camping bag that serves as an affordable backpacking bag as well.
The ALPS Crescent Lake 20 packs good warmth and practical features into an inexpensive package. For most car campers, the affordable rectangular shaped bags deliver better value. But if you're looking for a bargain on a synthetic bag for that can cross over into short backpacking trips, this is a good choice.
If you want a roomier than average, fully-featured synthetic mummy bag, consider the Crescent Lake 20. Higher quality and more expensive mummies with synthetic insulation will be more durable over time, but this is a good, warm bag for the price.