BirdTrout
North Branch Au Sable River, Michigan
37 mapped river miles, draining 312 square miles across Crawford county, in the Au Sable River watershed. A USGS gauge stands in it, but its record is too short for a measured July mean, so what this page knows about its temperature is today's reading and MDNR's classification of the water itself.
50°F and colder is cold, through cold-transitional and cool, to warm above 70°F — the same four bands, breaking at 58, 64 and 70°F, that the app paints. Grey is water nobody has measured.
The nearest live reading
This gauge stands in the North Branch Au Sable River. Its record is too short for a July mean, so the class below is MDNR's — but the reading is this water.
The pills above go to USGS. These are this site's pages for the same gauges — a thirty-day chart, the monthly means, the record, and today's reading against the five-year normal for today: 04135800.
The character of the water
A river by size, 37.0 mapped miles at a median width of 29.9 feet, fifth order, draining 312.29 square miles of the Au Sable River watershed in Crawford County. Twenty-five miles hold Blue Ribbon designation, from Dam No. 2 down to the Main Branch AuSable, and 17.0 miles are Type 1, last Saturday in April through September 30th, creel 5 fish with no more than 3 trout 15 inches or greater. A 2019 survey on gear-restricted water, mean width 108.24 feet, found brook and brown trout at 1,226 per acre, 31 pounds per acre. Brook trout went into an unnamed tributary in 2014, 0.0 per mile. MDNR types only 0.9 miles, 2 percent, across four short reaches, warm at river mile 34.3 to cold-transitional below 10.3; that class describes the valley segment and no temperature is measured here. The Au Sable River receives it at river mile 0.0. Chub Creek enters at 28.4. One walk-in access site; seven public units total 267,932 acres.
Thermal classification
MDNR types this water from its valley, not from a thermometer in it. A class, not a temperature — no July mean, because none was measured here.
| Reach | Typed miles | Band | MDNR type |
|---|---|---|---|
| RM 34.3–34.2 | 0.1 | warm | Warm stream · low gradient |
| RM 28.3–28.3 | 0.0 | cool | Warm transitional stream · medium gradient |
| RM 28.3–23.1 | 0.2 | warm | Warm small river · low gradient |
| RM 10.3–0.0 | 0.6 | cold-transitional | Cold transitional small river · low gradient |
MDNR has classified 0.9 of the 37 miles NHD carries for this stream — 2% of it. The typed water splits 0.6 mi cold-transitional, 0.3 mi warm, 0.0 mi cool. The untyped reaches are not warm water — they are water MDNR's inventory does not reach, and the mile ranges above span only the reaches it does.
Named stretches
Anglers name parts of this river. These are the names two or more independent sources use; each page says which sources, because a nickname is the one thing on this site that is not a measurement.
- North Branch Flies-Only — The North Branch below the Sheep Ranch access, through Lovells and down to the mainstem confluence — slick pools, spring seeps and a wild brook trout population that has never needed stocking.
Questions about this river
- North Branch Au Sable River fishing report — what it reads right now
- When to fish the North Branch Au Sable River — hatches, seasons and temperature
- How to get to the North Branch Au Sable River — access, parking and public land
- North Branch Au Sable River fishing regulations — season, size and gear by reach
- Is the North Branch Au Sable River good for brook trout?
- Is the North Branch Au Sable River good for brown trout?
Regulations
MDNR trout stream types, as designated. Types on file cover 17.0 of the 37.0 mapped miles; 20.0 miles carry no type in this dataset. Always check the current Michigan Fishing Guide before you fish — this is a copy, and the Guide is the rule.
| Type | Where | Season | Minimum sizes |
|---|---|---|---|
|
Type 1 17.0 mi |
RM 37.0–19.7 | Last Saturday in April–September 30th | Brook trout 7", Brown trout 8", Rainbow trout / steelhead 10", Lake trout 10", Chinook salmon 10", Coho salmon 10", Pink salmon 10", Atlantic salmon 10" |
Creel across all types: 5 fish, with no more than 3 trout 15“ or greater. Zero (0) Arctic Grayling. Tackle: Artificial lures and all types of natural bait may be used.
Blue Ribbon. North Branch AuSable River (BR 16), 25.0 mapped miles. MDNR's limits, verbatim — upstream: Dam No. 2; downstream: Main Branch AuSable.
Access
1 mapped MDNR access site within a quarter mile of the water, upstream first: North Branch Au Sable River At Morley's (RM 4.4). 1 walk-in, 0 boat or canoe launches.
Public land on the river
7 units of public or open-access land touch this river, 267,933 acres in total. Acreage is the whole unit, not the part beside the water.
| Unit | Owner | Acres |
|---|---|---|
| Grayling Management Unit | Michigan DNR | 130,704 |
| Au Sable State Forest - Grayling Unit | Michigan Department of Natural Resources | 89,732 |
| Mackinaw State Forest - Gaylord Unit | Michigan Department of Natural Resources | 33,636 |
| Kirtland Warbler Unit Lovells | State Dept. of Natural Resources | 9,904 |
| Camp Grayling Military Reservation | State Dept. of Natural Resources | 3,790 |
| Ausable River | Michigan DNR | 131 |
| Forestry | Michigan DNR | 36 |
Species
MDNR's most recent survey on this river ran in 2019 at North Branch Au Sable River, Crawford County, in a channel averaging 108.24 feet: brook trout, brown trout, at 1,226 trout per acre and 31 pounds per acre. MDNR strata: medium, land-locked, wild trout; regulation at the station, gear restricted.The station has been surveyed in 50 years since 1957.
Stocked, per the MDNR record: Brook trout. The most recent plants are Brook trout at Unnamed Tributary (Crawford Co., through 2014).
Hatches on this water
53 insects are recorded from northern lower Michigan, which is the region this river sits in. That is a claim about the region and not a survey of this stream: nobody has recorded which of them has been caught here. Open the river in the app and the hatch panel will narrow it to the ones whose temperature window today's reading is inside.
| Insect | Peak | Water | Size |
|---|---|---|---|
| Fish Eggs Other |
October–January and April | 33–60°F | #10–16 |
| Little Black Stonefly Allocapnia / Capnia spp. |
January–April | 34–46°F | #16–18 |
| Little Brown Stonefly Taeniopteryx / Strophopteryx spp. |
February–April | 38–50°F | #12–16 |
| Blue-Winged Olive Baetis spp. |
March–May and September–November | 38–58°F | #16–22 |
| Blackfly Simulium spp. |
April–June | 40–65°F | #18–22 |
| Blue Quill Paraleptophlebia adoptiva |
April–May | 44–56°F | #16–18 |
| Cranefly Tipula spp. |
April–June and September–October | 40–65°F | #6–10 |
| Grannom Brachycentrus spp. |
April–May | 48–58°F | #14–16 |
| Green Rock Worm / Green Weenie Rhyacophila spp. |
April–June and September–October | 45–68°F | #10–14 |
| Hendrickson Ephemerella subvaria |
April–May | 45–58°F | #12–14 |
| Little Black Caddis Chimarra atterima |
April–May | 46–58°F | #16–20 |
| Alderfly Sialis spp. |
May–June | 52–66°F | #10–14 |
| Caterpillar Lepidoptera larvae |
May–September | 55–75°F | #8–14 |
| Crayfish Orconectes spp. |
May–October | 55–78°F | #4–8 |
And 39 more — the year-round records, mostly: midges, scuds and sculpins, which are in the water every day and are therefore never the news.
Tributaries and watershed
5 named streams meet this one. Confluence miles are above the mouth; the longest twelve are listed.
- Au Sable River 137.7 mi · RM 0.0
- Crapo Creek 8.0 mi · RM 22.5
- Big Creek 5.9 mi · RM 5.4
- Chub Creek 5.0 mi · RM 28.4
- Carter Creek 1.3 mi · RM 2.4
North Branch Au Sable River sits in HUC 8 04070007, the Au Sable River watershed, and drains 312 square miles, Strahler order 5 at the mouth. 52 NHD reaches carry the name for 37.0 miles in total.
Other water nearby
The closest 6 rivers on this site, straight-line from the middle of this one — not drive time.