Madison River Hatch Chart & Bug Guide
Because “match the hatch” beats “cross your fingers.” Dates slide with snowpack and weather, but this calendar keeps you in the ballpark.
| Approx. Window | Insect | Size | Water / Notes |
|---|---|---|---|
| Late Jan – Mar | Midges (Chironomidae) | 18–22 | Slow side channels; fish before noon. |
| Early Apr | Skwala Stone | 10 | Warm afternoons below Palisades. |
| May | Mother’s Day Caddis (Brachycentrus) | 14–16 | Thick on Lower Madi; evenings explosive. |
| Late Jun – Mid Jul | Salmonflies (Pteronarcys Californica) | 4–8 | The big show; starts around June 25 and crawls upstream |
| Late Jun – Jul | Golden Stones (Hesperoperla pacifica) | 8–12 | Follows salmonflies by a week or so |
| July – Aug | PMDs | 14–18 | Cloudy mornings; emerger film eats. |
| Mid Jul – Aug | Hoppers, Ants, Beetles (Terrestrials) | 6–14 | Banks 11 AM‑4 PM when wind kicks up. |
| Late Jul – Sept | Callibaetis | 14–16 | Still‑water runs & side channels |
| Sept – Oct | Blue Winged Olives (Baetis) | 18–22 | Overcast afternoons, especially in the canyon. |
| Year‑round | Caddis & Sculpin | 10–16 | Caddis pop most evenings; strip sculpin all seasons. |
Reading the river to pick flies
- Water clarity: If runoff browns things out >18 in visibility, swap to a black/coffee Rubberlegs and a #14 San Juan.
- Water temp: Salmonflies need 52 °F to pop; carry a stream‑thermometer.
- Barometer: Post‑thunderstorm drops trigger epic hopper afternoons.