Au Sable River

The Au Sable's mainstem below Grayling is the river American trout conservation was born on. In 1959 sixteen anglers met at George Griffith's cabin on its banks and founded Trout Unlimited, tired of the state dumping hatchery fish into water that could grow its own. What they were protecting is a spring-fed river of almost unnatural consistency — cold, clear, and stable year-round because it runs on groundwater instead of snowmelt or dam releases. The crown of it is the "Holy Water," roughly nine miles from Burton's Landing down to Wakeley Bridge that has been flies-only, catch-and-release since the 1980s. This is wild brown and brook trout water, and it fishes like a big spring creek: soft currents over gravel and sand, cedar sweepers on the banks, and trout that get a long, unhurried look at your fly.

It's an intimate, wadeable river up top and a float river as you go down. Through the Holy Water you can wade the gravel at most flows, though the 250-400 CFS band on the Red Oak gauge will push you around and the sand between the gravel bars is soft. Below Wakeley the river widens, deepens, and becomes classic Au Sable riverboat water — the long, narrow, flat-bottomed wooden boats built to slip these shallows, poled by guides down toward Mio. The signature event is the Hexagenia limbata hatch, the giant "Hex" mayfly that comes off after dark from mid-June into early July and peaks the last week of June. It's night fishing in the truest sense: you're on the water before dark, listening for the biggest browns in the river to start eating size 6-8 duns you can barely see, tippet at 2X-3X because the fish that show up are the ones you came for. Outside the Hex, this is a match-the-hatch dry-fly river with a dense, reliable calendar — Hendricksons and Black Caddis in spring, Sulphurs and the drakes in late May and June, tricos and terrestrials into summer.

The trade-offs are honest ones. The Holy Water gets crowded — it's famous, it's close to the road, and everyone knows the Hex dates, so you're sharing it in late June. Because the river is groundwater-fed it doesn't blow out like a freestone, but summer heat is the real concern: during heatwaves the mainstem can climb past 70F by afternoon, and the ethical move is to fish early mornings and cool nights and leave the fish alone when it's warm (Gates Lodge itself calls the fishery off on 70-degree days). Grayling has everything you need — fly shops that have been on this water since 1936, guides, food, and lodging — and if the mainstem is warm or crowded, the North and South Branches and the cold trophy tailwater below Mio Dam are all short drives away.