Big Agnes Fly Creek UL 850 RDS DownTek Ultralight Sleeping Bag – 25°F, Regular

Overview

The Big Agnes Fly Creek UL 850 RDS DownTek Ultralight Sleeping Bag blends backcountry versatility with featherweight construction. With a 25°F comfort rating and a design that doubles as a traditional mummy bag and a FlipIt Footbox quilt, this piece of gear adapts to changing conditions without burdening your pack.

Constructed with ultralight NetPlus nylon ripstop, sourced from recycled fishing nets, it pairs with high-quality 850-fill DownTek down to deliver an impressive warmth‑to‑weight ratio. The result is a compact sleep solution that stays warm, compressible, and ready for long days in the outdoors.

Two-in-one versatility and loft

• Two-in-one design: switch between a traditional mummy bag and a quilt-style setup using the FlipIt Footbox for open airflow or full enclosure.
• Diamond quilting helps hold loft in place while using fewer stitches, contributing to a lighter overall package without sacrificing warmth.

Thermal efficiency and comfort

• Insulated draft collar and an ergonomic footbox work together to minimize drafts and maximize warmth retention.
• Low-profile cordlocks crafted with renewable materials offer reliable adjustments without adding bulk.

Packability and long-term care

• Includes mesh storage sacks for long-term care and compact stuff sacks for trail use, plus compatibility with Big Agnes Compression Stuff Sacks for minimal packing size.
• Designed to compress into a small footprint, helping you keep a lighter, more agile pack setup on multi-day trips.

Real-life use and benefits

Ideal for backcountry hikers, weekend warriors, and ultralight explorers who value flexibility and warmth without extra weight. The 25°F rating is a guide for cooler nights, while the two-in-one design offers options when temperatures shift. Sustainability-minded trekkers benefit from recycled-material fabrics paired with responsibly sourced down, all in a compact, easy-to-care-for package.

• Backcountry overnight comfort with an adaptable setup for changing conditions.
• Lightweight warmth that pairs well with a quality sleeping pad for cool-weather campouts.

Notes on use

Expect warmth to vary with external conditions and sleeping pad choice. The FlipIt Footbox option allows you to tailor airflow and enclosure as needed, offering a flexible approach to staying comfortable in unsettled weather.