The upper San Juan around Pagosa is an interesting winter fishery as hot spring inflows help water temps stay a little warmer. Its still winter fishing, so you will need to dial your nymph rig just right though. Attractor nymphs with smaller nymphs droppers will be your friend.
Patterns/Bugs:
Nymphs: Prince nymphs 14-18, Pats Rubberlegs 8-12 or Jigged Pats 8-12, Black and Blue Copper Johns 14-18, Pheasant tails 18-22, Juju Baetis 18-20, Disco Midge 18-20, Rainbow Warrior 18-22, Flash Midge Pupa 18-22.
Hey bud, you are reading the San Juan River report here, probably thinking Should I go fish the Juan this weekend. The answer is, yes you should. Its a tailwater, and its the winter, and while you may be wishing for some bucknasty high country brookies (max 10), just go fish the San Juan. Its winter and a fun time, and they are eating bugsmostly nymph bugs but who cares? Bring a friend and have fun.
Patterns/Bugs:
Attractor nymphs: Leech patterns: Mayers Mini Leech 8-14, Bunny Leech, Simi Seal Leech, Pine Squirrel Leech San Juan Worms, Egg patterns, Small Mop flies, and Annelids in 18-22.
Midges 20-26: Black Flash Midge Pupa, Tavs Big Mac, Bling Midge, Grey and Olive Midge Pupa
Midge Dries: Griffith Gnat 18-22, Bunny Midge 20-24.
BWO Nymphs: Foam Wing RS-2s 20-24, Killer May 20-24, Juans Sniper Baetis 22-24, Juans Jedi Master 22-24, All Flavors of WD-40s #20-24.