Chocolay River

The first of the Au Sable's Big Five, starting the last week of April and peaking the first two weeks of May on the northern rivers. Duns emerge mid-afternoon (roughly 2-5 pm on the Au Sable) for one to two hours, and spinners return to the riffles late afternoon to dusk, often compressed into a half hour; cool evenings push the spinner fall to the next morning. Fish a Pheasant Tail or dark-wingcase nymph before the hatch, then an emerger or Regan's Hendrickson Parachute (#14) during it, and a rusty spinner at dusk. The male dun is the darker Red Quill, tied a size smaller.

A big mottled-wing clinger that hatches sporadically from mid-May into July, late morning through evening with a mid-afternoon peak, rather than in dense flurries. Duns take a long time to get off the water in the riffles, which makes them a good target for a #10-12 parachute or Comparadun drifted through fast water and along seams. Nymphs are flat clingers on cobble; a March Brown or Hare's Ear nymph fished in the riffles before the hatch works. Ignore aggregator charts that start this hatch in March; no Michigan shop supports that.

The pale summer clinger of June through mid-August, coming off in the afternoon and evening on the Upper Manistee, Au Sable and Muskegon. Hatches are scattered rather than heavy, so the Light Cahill is often a searching pattern: a #12-14 cream parachute fished through riffles and pocket water on summer evenings. Spinners fall at dusk over the riffles. A Robert's Yellow Drake covers Cahills, Sulphurs and Brown Drakes in one Michigan pattern.

The longest-running mayfly on the Michigan calendar, from mid-April through late October, with the biggest brood the first week of May, a second in mid-June and a third in September. Duns come off midday to mid-afternoon and are best on gray, drizzly days; the tailwaters below Croton and Tippy dams keep BWOs going through the winter. Fish a #18-20 CDC or Sparkle Dun for risers, a Pheasant Tail or olive nymph before and between hatches, and a rusty olive spinner in the evening. Sizes shrink through the season, so carry #16 in spring and #20-22 in fall.

The all-summer caddis of Michigan rivers, from May through September and heaviest in early-to-mid July, when the Manistee system's caddis abundance peaks an hour or two after sunset. The Trails to Trout chart splits it into Spotted Sedge (#12-16, from May 1) and Cinnamon Caddis (#14-18, from May 20); both are net-spinners that emerge slowly through the film, so a sparkle pupa or soft-hackle swung at dusk is often the best fly. Larvae are available year-round in the riffles and are a steelhead and trout staple. For the egg-laying flights at dark fish a #14-16 tan elk-hair caddis; on the Muskegon the cinnamon caddis (#16) starts mid-May and the tan/olive caddis fishes into August on the Upper Manistee.