Paradise Valley, Montana

Best Flies For Yellowstone River

Updated Apr 24, 2026, 7:18 AM MDT

Fish the softer banks, side channels, and gravel transitions with stoneflies, worms, and baetis nymphs until you see consistent heads.

Current Conditions
  • Flow: Mainstem volume is higher than the trout rivers around it, but side channels and softer inside bends stay very workable in spring.
  • Water Temperature: Water is still cold enough that feeding windows tighten around the warmest part of the day.
  • Weather: Wind changes the whole river. Stable clouds are better than bright sun or hard gusts.
  • Overall Rating: 6/10
Today's Read

Yellowstone River is fishing around blue-winged olives and midges. Start with the patterns below and adjust only after fish show you something different.

Best Flies Right Now
  • Pat's Rubber Legs, size 6-8, nymph
  • Worm pattern red or pink, size 8-12, nymph
  • Lightning Bug, size 16-18, nymph
  • Pheasant Tail, size 16-18, nymph
  • Parachute BWO, size 18-20, dry
What They Match
  • Blue-winged olives, size 18-20, midday to afternoon
  • Midges, size 18-22, sheltered water in the morning
  • March Browns, size 12-14, sporadic midday in softer runs
How To Fish These Flies
  • Cover inside bends, seams behind gravel bars, and the slow edge beside heavier center-river current.
  • A bigger lead fly with a smaller mayfly trailer is the simplest way to find fish before surface activity starts.
  • If bugs appear, move to protected slicks and side channels where trout can rise without fighting the main current.