Recently the water in Yellowstone National Park has been fishing well. The Madison, Firehole and Gibbon would be a great place to start. Look for BWO's and Caddis in the morning. Once things warm up throw terrestrials. The Madison and Firehole can be very fun swinging soft hackles and stripping small streamers. Lots of options. Other then the western region of the park the Gardner river near the north entrance is also fishing well. Fish those deep holes to find some big browns that have run up from the Yellowstone. You may have to let it warm a bit in the morning due to cold temps at night. Look for BWO's on cloudy days. You should also see Caddis in the morning and evening. Mid day fishing will call for streamers, nymphs, midges, and terrestrials. Swinging soft hackles is our favorite technique this time of year and can produce fish all day long!
 
 
Flies to use:
PT Nymph sz 10-18
Prince Nymph sz 10-18
BH Hares Ear Nymph sz 12-16
Soft Hackle PT Nymph sz 12-18
Soft Hackle Hares Ear sz 10-12
Delekta's Big Spanker Purple, Green, PT sz 12-16
Delekta's Little Spanker Silver, PT, Olive sz 12-16
Pat's Rubber Legs Black/Brown sz 8-12
Morrish's Dirty Bird Natural sz 12-16
Morrish's Foam Hopper Gold, Tan, Pink sz 10-14
Chubby Chernobyl's Gold, Tan, Pink, Purple sz 8-12
Parachute Adams sz 12-20
Parachute Purple Haze sz 12-18
Wilcox's Low Rider BWO sz 18
Matthew's Sparkle Dun BWO sz 18-20
 
Griffith's Gnat sz 20
Zebra Midge Black, Red sz 20
Elk Hair Caddis Tan, Dun, Brown sz 16-18
X-Caddis Tan sz 14-16
Zonker Olive, Natural sz 6-10
McCune's Sculpin Natural sz 6
Slumpbuster Natural, Olive, Black sz 8-10