I fished the Au Sable last Thursday through Sunday. It’s been hot there. Very hot. The mid-90s some days, without a cloud in the sky. It looks like it will be a little cooler next week, but still very warm.
Between the heat and the nocturnal habit of browns in the Au Sable, you’ll want to be on the water not long after dawn if you’re able, and fish through 10:30 or so. Then hit the river again after 7 and fish until last twilight at 10:15 – or if you’re bold and find a piece of river where you know every submerged log, stay out until 2 in the morning and swing mice for big browns. This schedule will have the added benefit of missing most of the mid-summer “aluminum hatch” -- the clueless canoers from one of several liveries.
This time of year, your best bet is the Holy Waters of the mainstream, which is the flies-only, catch-and-release section that runs between Burton’s Landing on the upstream end and Wakeley Bridge on the downstream end. That’s the coldest part of the river system, and the very coldest part is in the mid-section around Stephan Bridge. Which is the location for Gates Au Sable Lodge, fly-fisherman central for the river. Stop in the shop there, I think they have some single-sheet maps, and they’ll probably direct you to good piece of water. The Hungry Fisherman restaurant there has a takeout window where you can get really good sandwiches to pack for your day out.
Josh at Gates Lodge updates the fishing report about once a week this time of year, and looking at the report that just went up, it looks like the daytime fishing has improved with cooler temperatures. It’s a nice report, as much essay on the changing seasons of the river as it is a hatch report. https://gateslodge.com/fishing-report/
Grab a handful of Skunks while you’re in there, a local summer attractor-pattern with a black chenille body, deer-hair wing and white rubber legs – grease it up, throw it with a big splash into the slack water behind the log jams, try to get a decent drift if you can, then let it wake on the surface or swing under the surface film. Also get some tricos and size 18 and 24 blue-wing olives so you’ll be ready for the hatch.
If you’re really serious, buy one of the spiral-bound guide books to the river by the Challenge Chapter of Trout Unlimited. I think they’re around $32 now, but they’re worth every penny. They map every two-track road with public access to the river, and many of these sites are unmarked or look like private property. Generally, the sites on the north side of the river, off North Down River Road, get less traffic than the sites on the south side off M-72.
Most sections of the upper- and mid-Holy Water are very wadeable with a mix of sand and gravel -- knee-deep or less except for the deeper runs and pools. I’ve heard it called Old Man Water.
The weekend of July 28-29 will be the busiest weekend of the year in Grayling and on the mainstream. The Au Sable River Canoe Marathon starts at 9 p.m. July 28 in Grayling and runs all night for the next 120 river miles to Lake Huron. It’s billed as the “World Toughest Spectator Race,” and people drive from bridge to bridge to cheer them on in the dark. It’s kind of a big rolling party and a lot of fun.
--Alan from Detroit