Big Agnes Fly Creek UL 850 DownTek Ultralight Sleeping Bag (50°F Zip Quilt) – Regular

Flexible sleeping solution for diverse adventures

The Big Agnes Fly Creek UL blends ultralight engineering with adaptable warmth. Use it as a traditional mummy bag for snug warmth on cold nights, or switch to the FlipIt Footbox quilt for open, breathable comfort when conditions loosen. This convertible design suits variable camp setups, from alpine evenings to shoulder-season treks, without adding unnecessary weight to your pack.

• Versatile two-in-one design: mummy bag or open quilt
• Compact, lightweight footprint ideal for fast-moving trips
• Low-profile adjustments keep the silhouette slim on the trail

Ultralight materials with real-world warmth

The shell uses Ultralight NetPlus nylon ripstop, crafted from recycled fishing nets, paired with 850-fill DownTek insulation. This combo delivers a strong warmth-to-weight ratio with water-resistant properties to help shed morning moisture after damp nights in tents or shelters.

• NetPlus ripstop for durable, lightweight performance
• 850-fill down offers lofty warmth without bulk
• DownTek treatment adds natural water resistance

Signature quilting for loft and efficiency

Big Agnes Signature Diamond Quilting keeps down in place with fewer stitches than traditional quilt lines. The result is reliable loft and warmth while trimming weight, so you can rely on it night after night without carrying extra bulk.

• Diamond quilting reduces down migration
• Lower stitch count means lighter overall weight
• Loft retention supports comfortable sleep in chilly camps

Thermal efficiency designed for outdoor nights

Insulated draft collars, an ergonomic footbox, and renewable-material low-profile cordlocks work together to minimize drafts and maximize warmth retention. The system is built to feel responsive to your movement and the changing night air, helping you stay comfortable without overheating.

• Draft collar helps seal out cold air
• Ergonomic footbox supports natural leg position
• Renewable-material cordlocks reduce weight and bulk

Packability and care on the go

Both configurations include mesh storage sacks for long-term fabric care and compact stuff sacks for trail use. When you need to shrink the pack size further, the system plays nicely with Big Agnes Compression Stuff Sacks, supporting minimal packed dimensions for multi-day treks.

• Mesh sack for breathable aging and maintenance
• Compact stuff sack for trail-ready packing
• Compatibility with Compression Stuff Sacks for smaller packs