Cross Mountain 45°

Synthetic fill Big Agnes System bags designed to excel in all conditions and provide more room than a mummy bag

Synthetic fill Big Agnes System bags designed to excel in all conditions and provide more room than a mummy bag

Our Classic Synthetic bags offer great value and high quality materials including Insotect Hotstream® insulation, featuring 100% recycled material, which feels as warm and soft as down insulation. Whether you're looking for your first bag or want to add a synthetic option to your gear quiver, campers of all levels will appreciate the versatility of these Big Agnes System bags. Made thermally efficient with A-Shingo™, A-Flex™, or quilted construction, you'll notice the total body insulation right away. Slip any rectangular 20" wide pad into our full pad sleeve design and you are ready to go.
$149.95 to $159.95
100% Guarantee


Our top priority is to provide customer service as stellar as the award-winning products we create. If one of our products does not perform to your satisfaction, contact our customer service team and we will help you find gear that fits your needs.
$149.95 to $159.95

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Specs + Sizing

Bag WeightReg: 1lb 10oz / 737g / Long: 1lb 13oz / 822g
Fill WeightReg: 11oz / 312g / Long: 12oz / 340g
Compressed Bag SizeReg: 7.5in x 6in / 19 x 15cm / Long: 7.5in x 7in / 19 x 18cm
Stuff Sack SizeReg: S 7.5in x 15in / S 19 x 38cm / Long: S 7.5in x 15in / S 19 x 38cm


Design improves connection between pad sleeve and bag providing a roomier sleeping space without adding bulk

Sculpted contour allows the bag to drape around you, increasing insulation performance

Free Range Hood design gives you the freedom to lift your head while snuggled in the hood

Low profile cordlock lets you un-cinch the hood with one hand

Stretch panel on pad sleeve doubles as pillow stabilizer

Our softest, technical sleeping bag fabrics yet - smooth and soft to the touch

Zipper Garage

Mate together left and right zip bags

Interior fabric loops for sleeping bag liners

Exterior loops for hang drying or storage

Mesh storage sack & nylon stuff sack

Construction + Materials

Nylon rip-stop shell fabric with a water repellent finish

Nylon taffeta lining

Quilted construction

Hotstream® by Insotect - 100% recycled polyester insulation

70"/178cm YKK #8 zipper

61"/155cm YKK #8 zipper

Vaulted foot box creates more wiggle room for your feet

Rectangular shaped bag

Integrated full pad sleeve

Here’s what other people think.

What’s in a Name?

In the late 1970's, ABC's American Sportsman TV show filmed a river trip into the Cross Mountain canyon on the Yampa River. The first rapid is the Osterizer hole and the film crew got what they were looking for - carnage! One of the kayakers got totally worked and had to be airlifted by helicopter to a local hospital. Don't worry, he's fine. Nowadays when you mention Cross Mountain around a group of Steamboat local boaters, they just ask, When? It has become the classic Class IV/V desert canyon river run.