Mother’s Day Caddis Hatch Outlook and Tactics
It’s almost that special time of year when the fish can go crazy eating olive-bodied caddis for a few days on the Yellowstone before the river blows out. It’s been a couple seasons since the stars aligned, but because of recent heavy rains that should flush the low-elevation snow and a forecast for temps in the 60s (good) rather than warmer (bad) for the next week or so, we have at least a decent shot. Here’s a detailed outlook, plus tactics that will work on the Yellowstone (where the hatch can be epic or can be washed out by snowmelt) and on the Madison (where the hatch is usually decent but not epic).
I’d say we have a 50/50 shot at a fishable caddis hatch on the Yellowstone this year. It depends on how much it rains this upcoming week and where the snow line is. Late last week saw the warmest temps of the season, up to the low 70s at valley-level, and this combined with heavy rain yesterday (Saturday 4/20) and this morning has caused the Yellowstone to spike to 2900 to 3500 cubic feet per second flows, roughly twice the seasonal average.
The river is muddy right now. Provided on how much it cools off, and it is supposed to cool off sharply Monday-Wednesday, we should have a fishable window mid-late week to get us close to the end of April. I do not expect any or at least many caddis this week. Water temps will still be in the 40s and it takes consistent 50-53 degree temps to get them really popping. Streamers are likely to be the ticket instead.
The key is the period beginning next weekend, April 27 onward. Temps in the week thereafter will determine whether we get a fishable hatch. If the NOAA forecast pans out, we are in good shape. The forecast is calling for cooler than normal temps and below normal precip for this period. This would be ideal to keep runoff from starting early. We’ll see… The most likely period for the hatch will be the first week of May. After that, temps are supposed to spike and that’ll be the end of the spring fishing on the Yellowstone.
The entire river from Gardiner to the mouth of the Shields River should be clear enough if the hatch does pop while the river’s clear. Even before yesterday’s rain, the river was filthy below Biltman Creek in Livingston, but the rain should have blown out most of the remaining low snow in this creek’s drainage. Once it drops, this will open up more clear water. It is unlikely the Shields River will clear enough to make the area east/downstream of its confluence fishable again this spring. There’s too much snow in the Shields Drainage, which is south-facing and therefore melts quick.
Over on the Madison, expect the caddis to pop in mid-May. While seldom as epic as the Yellowstone hatches, the Madison hatches pretty typically offer at least decent fishing for a week or more in mid-May.
Subsurface tactics are usually more effective during the Mother’s Day Caddis hatch than dry flies, and attractor dry flies are usually more effective than imitative ones.
Start your day of fishing with streamers or by nymphing deep. Flashy streamers like the Kreelex are good choices in the spring as the water gets dirty. Run a caddis pupa like my Mother’s Day Pupa as a second chance fly behind this streamer. A lot of fish will take the dropper if the caddis hatch is imminent. If nymphing, something like a Prince or my Hula Princess on the bottom with an upper dropper of a lighter caddis pupa is a good choice. Another option is to fish a stonefly nymph with the Prince or a heavier pupa behind it.
Once you start seeing a few rises and a few caddis fluttering, switch to something like a #14 Peacock Clacka Caddis or Coachman Trude with the Mother’s Day Pupa or Prince on the dropper. Except in intense hatches, you can stick with this rig for the remainder of the hatch. Look for hatches to be heaviest from early afternoon through early evening. Early and late in the day won’t do much for you.
If the fish really start going crazy, swap the pupa for an olive Mercer’s Missing Link Caddis or Lawson’s Spent Partridge Caddis in olive. These double-dry tactics will work best in areas where bugs will cluster: foam patches, large eddies, and the like. They’re also a better bet if you’re wade-fishing than floating, since when wading you can pound areas you find rising trout and sort of encourage them to rise. From the boat, you’re flock-shooting and so better off most of the time targeting the larger numbers of fish eating pupae subsurface.