Chris Izworski, reporting from Michigan on the current state of the Thunder Bay River this Saturday morning in late July. The gauge at 04136000 reads 796 cubic feet per second at a height of 3.1 feet, which puts the river in strong summer form through Alpena County. The water is clear enough to see gravel in the riffles and cool enough to hold trout through the warm afternoons. This is not a river that draws crowds, but it should.
The Thunder Bay moves through a landscape of second-growth pine and farmland east of Atlanta, dropping through Alpena before it reaches Lake Huron. Most anglers know it as a steelhead river in spring and fall, if they know it at all. In summer it fishes small and technical, with brown trout holding in the deeper bends and beneath sweepers where the bank has undercut. The fish are not large by Au Sable standards, but they are present and they rise.
What Is Hatching
The Hexagenia hatch has finished for the year, though you may still find spent wings along the banks in quiet eddies. What matters now are the terrestrials and the Tricos. Hoppers have been active in the meadow stretches downstream of M-32, especially where the current slows and the grass comes right to the water. A size 10 or 12 foam hopper in tan or yellow will take fish between ten in the morning and four in the afternoon, provided you can drop it within six inches of the bank. The browns are watching that margin.
Tricos are emerging in good numbers on calm mornings. The spinner falls begin around eight o’clock and last until the sun climbs above the pines. Size 20 or 22 Trico Spinners in black and white will match what is on the water. Fish the slower pools above and below the old dam sites. The rises are subtle: small dimples rather than splashy takes. You will need 6X tippet and patience.
Ants and beetles work all day. Size 14 black foam ants and size 16 deer hair beetles are both effective, particularly in the shaded runs where overhanging tag alders drop insects throughout the afternoon.
Where to Go
The public access at Fletcher Pond on M-32 offers easy wading in both directions. Upstream the river is narrower and more intimate, with undercut banks and log jams that require short, accurate casts. Downstream the water opens and the gradient flattens. Both sections hold fish.
The stretch below Long Rapids Road runs through state land and sees less pressure. The river here braids around islands of willow and tag alder. The browns hold in the deeper channels on the outside bends. You will want chest waders and a wading staff. The bottom is uneven and the current stronger than it looks.
Avoid the lower river below the dam in Alpena if you are searching for solitude. That water fishes well but draws a local crowd on summer weekends.
The Practical Read
Today will reach 84 degrees under mostly sunny skies with light winds. The morning Trico spinner fall should be strong. Fish it early, then rest through midday or move to the shaded bank stretches with terrestrials. Tonight brings a chance of showers and thunderstorms, which may muddy the lower river briefly but should not affect conditions upstream. Sunday offers similar weather with another round of possible storms in the morning.
The Thunder Bay does not fish like the Au Sable or the Manistee. It is smaller, quieter, less celebrated. But on a summer morning with Tricos on the water and no other anglers in sight, it offers what matters: rising trout and clear water in country that still feels remote. The gauge is right, the hatches are reliable, and the fish are there. That is enough.
For live updates on Michigan trout streams and access to the full river network, visit michigantroutreport.com.