That's My Bag.

   When one decides to sleep in the outdoors for extended periods of time one should carry with them a  3 season sleeping bag (or quilt, if that's your thing). You have two choices for insulation in a sleeping bag, synthetic or down. Down insulation is lighter and more compressible than synthetic, and has better insulating properties. The downside to down (pun unintended) is that it loses it's insulating properties when wet, and takes a long time to dry. Down is also more expensive. I decided to tough it out ;) and get the best goose down bag I could afford. A Big Agnes Mystic SL 15 deg. Down Sleeping Bag.

  
   The size regular Mystic SL weighs a mere 2.3lbs. (the SL stands for super light) and is filled with 15oz. of 800 fill goose down. The mystic is a squared off mummy bag. The squaring allows for more room than a standard mummy bag.

    Big Agnes SL bags use an integrated sleeping pad system and do not have insulation on the bottom. Rather than insulation (which would compress under body weight and loose most of it's insulating properties) the bag has a sleeve that allows a sleeping pad (not included) to be inserted. The pad provides the insulation and you don't roll off the pad while sleeping.

 

 The bag compresses into 8" x 12" in it's included stuff sack with enough room left over in the sack for clean boxers, socks, etc. That is a 2L. soda bottle in the picture.

   I used the bag for the first time on my overnight to Cronan Ranch, but the weather being so warm, I sweated profusely whenever I tried to cover myself with it. I am a hot sleeper and this bag, combined with a good insulated inflatable pad, should keep me warm at least down to the rated temp of 15 deg. Add wool socks, and long underwear and I'm good to go in any weather I'm likely to encounter.