Since we're still in the first couple of innings of the game this season on the upper Madison, I've put together a list of hatches that I consider most important, at least from a guide's perspective. There are likely dozens of other lesser known species of aquatic insects that hatch throughout the river, but for the purposes of angling and eliciting trout eats, these are the ones I focus on.
I've also boiled down the timeline of when those hatches occur. And again here, I've boiled down the timeline to those periods when each hatch is most relevant. For example, it's entirely possible to find BWOs on the upper Madison each month between March and November. Is it likely? No. So, I've simplified the chart to when they are most important from a trout's perspective. Interestingly, when you step back and think about this, I'm sure it's by no accident that each of these major hatches generally occur at a time when they're the primary show on the river, with a couple exceptions (Caddis and BWOs in the spring being one). For written summaries on these and other bugs on the upper Madison, head over to my HATCHES page.
So, while not ultimately exhaustive, this bug calendar is how I view the river from a guide's perspective which drives my strategy each day. Small black "x's" indicate potential for finding a hatch, while uppercase red "X's" indicate the primary time for a hatch.
As you can see, it's now March and the next big thing to happen is the Skwala stonefly hatch. While the upper Madison doesn't get quite the attention for the Skwala like some of the waters up around Missoula, I've noticed a decent hatch in the last few years especially around Ennis. It was around March 15 last year when I began seeing shucks from Skwalas on the banks at the town bridge. Looking forward to seeing what this year's hatch looks like. It's been unseasonably warm the last 2 weeks, so I'm thinking any day now we ought to see Skwalas.