So, I?m off to Colorado next week to fly fish (woo hoo!) and the forecast indicates the lows are going to be in the lower 30?s (F) and the highs are going to be somewhere in the 40?s with a good chance for rain. As I?m new to fly fishing (particularly in cold weather) I need some clothing advice.

I?m confident with what to bring regarding a layering / outer shell system for my upper body (I?ve backpacked quite a bit) however, I need some advice as to what you all would suggest I wear inside my waders (Simms G3?s) for these temps.

For my upper body I was planning on wearing a long sleeved synthetic wicking base layer plus a merino wool pullover. I?ll bring along a Patagonia micropuff, nylon windbreaker, and a rain jacket (stored in a waterproof bag in a small backpack). As far as heads and hands I?ll bring along some fingerless fleece gloves, a thin merino wool balaclava, and a wide brimmed hat.

As far as under the waders, I was leaning towards wearing a pair of synthetic boxer briefs, a pair of merino wool socks, and going ahead and wearing a pair of Patagonia capilene 3 (synthetic) long underwear to the stream that morning. This may seem like a dumb question but do you all also wear pants (e.g. fast drying nylon) over your long underwear as well? Also, the capilene 3 long underwear is pretty thick stuff, should I invest in a lighter weight base layer (perhaps thin merino wool)?

What would you bring along for your lower body?