The Land Report 7/07 Atom +40 Bag

The Ultimate Gear for Work and Play

With a comfort rating of +40 degrees Fahrenheit, this 1-pound bag is made for summer nights.

Adventure Cyclist 8/06 Atom

Lightweight, Durable, Packable

One of the lightest 40-degree sleeping bags you can buy, the Atom is the cousin to the 30-degree Helium we reviewed in the March issue. Marmot touts the Atom as a 16-ounce bag, though our sample weighed in at 18.5 ounces – still a 5-ounce savings over the Helium. Like the Helium, the Atom keeps its weight down by using ultra-high-loft 850-fill down, a Pertex Quantum Ripstop shell, and a half-length zipper (this same architecture is also used by a few smaller manufacturers to produce bags of similar weight). The 850-fill down is luxurious and an easy-access drawcord cinches the hood down snugly around your head on cold nights. I found the temperature rating to be accurate, though if you don long underwear and, say, a down vest, the bag could serve you well in conditions much colder. The Quantum fabric is outstanding – it’s soft, downproof, and supremely packable. For its weight the fabric is surprisingly durable, though probably not as durable as bags that weigh twice as much. But, hey, the Atom can pack down to the size of a large grapefruit, which is worth a lot when you’re traveling svelte.

Backpacker 3/06 Atom

Top Ultralight

Comfortable nights in near-freezing alpine camps in Washington’s Glacier Peak Wilderness convinced one tester that this 850-fill-power, 40 degree F bag was “impressively warm for such a featherweight.” On an 11-day expedition through Alaska’s Revelation Mountains, our Rocky Mountain editor watched a companion stuff his Atom down to the size of a large coffee mug – after sleeping snugly in 30s temps – while the rest of the group hauled 3-pound synthetics. Add a comfortable cut and well-contoured hood design.