The Sturgeon River in the western UP is running cold and clear this third week of April, which is exactly what you want it to be. The USGS gauge data is unavailable today, so you will have to trust your eyes and your instincts when you get there. What matters right now is that the water is still carrying snowmelt and holding the kind of temperature that makes brook trout aggressive without making them careless. The season is turning. The first real hatch fishing of the year is starting, and if you are planning a drive north, the decision is straightforward: the Sturgeon is worth it.
What to expect on the water right now
April on a coldwater UP stream means you are fishing the threshold between early season subsurface work and the emergence windows that will dominate May and June. The water temperature data from the gauge is not available today, but you can assume it is still in the 40s. That matters. It means the fish are feeding, but they are not yet in the kind of feeding frenzy that comes later. You will need to be precise with your fly choice and your drift.
Midges are the base layer right now. Mercury Midge and Zebra Midge in size 20 dead drifted under an indicator in the slow pools and eddies will produce fish on any day. Fish tight to the bottom. The Sturgeon has plenty of water that looks too slow to hold trout, and it does not. These pools are where your brook trout are spending energy inefficiently right now, and a dead midge presentation will find them.
Little Black Stoneflies are emerging along the banks, particularly where the current eases near the shore. A size 14 Little Black Stonefly dry will draw rises from fish that are watching the banks. If that does not work, drop to the nymph, size 14, and work it deep through the riffles where the insects are starting to crawl out. The Sturgeon has miles of riffle water, and the nymph game is productive and meditative.
Blue-Winged Olives are coming. Fish overcast days especially. The hatch is not consistent yet, but when conditions tighten and the light drops, tie on a Parachute BWO or Sparkle Dun in size 16, or go subsurface with an RS2 in size 18. Use 5X or 6X fluorocarbon tippet. These are small flies, and they demand precision.
The Hendrickson watch begins
The Hendrickson hatch is the reason many of us keep a calendar in April. The emergence here on the Sturgeon typically peaks in the afternoon, 2 to 4 PM, on days when the sun breaks through overcast skies and the water temperature edges into the low to mid 50s. You are not quite there yet, but you are close. If you make the drive this week, plan your day around the afternoon window. Fish the nymph, size 12 Hendrickson Nymph, through the riffles in the morning. Then move to the flats and the slower water where the duns will appear and where the fish will begin to rise. A size 12 Hendrickson Dry or Red Quill will be your answer.
Other insects worth noting
Early Brown Stoneflies are active. These are not yet the heavy spring creek stone hatches you might encounter downstream in the Lower Peninsula, but they are real, and they respond to wet fly work. Swing a Hare’s Ear Nymph size 12 through the riffles, or try skating a dry brown Elk Hair Caddis size 14 across the surface when you see the adults moving.
Grannom Caddis are starting. The Elk Hair Caddis size 14 skittered across the water will draw strikes from fish that have learned to look up. The X-Caddis size 14 fished in the film is a good alternative when the fish are being selective. If you want to work subsurface, the LaFontaine Sparkle Pupa size 14 swung through the riffles on the rise will connect you to fish that are eating the emerging pupae before they reach the surface.
Access and what to know
The Sturgeon flows through the Ottawa National Forest in one of Michigan’s most remote brook trout strongholds. Access points are available via Ottawa National Forest roads and US-45 crossings. The fish here are wild and beautiful, and the regulations exist to protect them. Check the current DNR regulations before you go. Artificial lures only apply in certain sections, and the special brook trout regulations are worth reading carefully.
Plan for a full day. Bring layers. The weather in the UP in April is not reliable, and the water is cold enough that a slip matters. The roads to the Sturgeon are reliable, and the river itself is worth the drive.
For live gauge data and current flow conditions, check https://trout.chrisizworski.com.