Paradise Valley, Montana

Yellowstone River Hatch Report

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 keyed to the bugs that are active in the current light and water conditions. These are the insects that matter right now and the windows when they matter most.

Current Hatch Report
  • 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
Flies To Match The Hatch
  • 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
How Fish Respond To This Hatch
  • Yellowstone fish are spread out more than they are on the smaller spring creeks and tailwaters, so the game is finding softer holding water inside a big river. Browns and rainbows sit on current breaks off the main push and slide shallow when baetis start drifting. They are rarely as selective here as they are on the Missouri or Bighorn, but they do want flies near the bottom before the hatch gets going.
  • Cover inside bends, seams behind gravel bars, and the slow edge beside heavier center-river current.