BirdTrout
Ontonagon River, Michigan
24 mapped river miles, draining 1,344 square miles, in the Ontonagon subbasin watershed. 1 USGS gauge report water temperature on it, and this page reads it.
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.
Water temperature right now
Live from the USGS — every pill above is live, so the numbers you are reading are the latest continuous readings at each gauge. Provisional and unreviewed, as all real-time data is. If that fetch cannot happen — you are offline, or the USGS is down — the pills fall back to the last value we cached, 30 September 2026, 13:43 UTC. None of them, in fact: Rockland is not reporting water temperature — USGS carries no water-temperature series for it at all. That pill carries a modelled temperature where one can be fitted, marked as modelled, and a dash where it cannot — never a stale reading dressed as a current one.
Thermal classification
Each gauge carries a July mean built from its own daily record — 6 Julys, 2019–2024, measured rather than modelled. A July mean is what decides which of the four bands a stretch of water belongs to, because July is when a trout river either holds or does not.
| Reach | July mean | Band | Groundwater |
|---|---|---|---|
|
Rockland RM 24.3–0.0 |
70.7 °F | warm | low |
Every gauge sits at the bottom of its segment, so each number is the warm end and the water above it runs colder. ±1.97 °F on the fit.
The lake run
The Ontonagon River is a Lake Superior tributary with 23.7 miles of run corridor on it — salmon, steelhead and lake-run brown trout, on their own calendar and under their own rules. Run timing, species and access on the Ontonagon River →
Questions about this river
- Ontonagon River fishing report — what it reads right now
- When to fish the Ontonagon River — hatches, seasons and temperature
- How to get to the Ontonagon River — access, parking and public land
- Ontonagon River fishing regulations — season, size and gear by reach
Regulations
MDNR trout stream types, as designated. Types on file cover 24.1 of the 24.3 mapped miles; 0.2 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 3 24.1 mi |
RM 24.3–0.0 | January 1st–December 31st | Brook trout 15", Brown trout 15", 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.
Fishable reaches
River miles are measured above the mouth, along the mapped mainstem. The reach breaks are the gauges, which is also how the temperature model divides the river.
| Reach | Miles | July mean | Access on it |
|---|---|---|---|
|
RM 24.3–0.0 down to Rockland |
84.1 | 70.7 °F | — |
0 mapped access sites on the mainstem: 0 walk-in, 0 boat or canoe launches.
USGS gauges
Every gauge on the mainstem, upstream first. Links go to the USGS monitoring-location page for the site.
-
Ontonagon River near Rockland
— 04040000 · RM 0.0
186 July days of record across 6 Julys (2019–2024) · 489 cfs at last read
Public land on the river
13 units of public or open-access land touch this river, 45,036 acres in total. Acreage is the whole unit, not the part beside the water.
| Unit | Owner | Acres |
|---|---|---|
| Ottawa National Forest | United States Forest Service | 18,899 |
| Ottawa National Forest | U.S. Forest Service | 13,288 |
| Copper Country State Forest- Baraga Unit | Michigan Department of Natural Resources | 4,668 |
| Northern Highland State Forest | State Dept. of Natural Resources | 2,000 |
| University of Notre Dame Environmental Research Center | University of Notre Dame | 1,767 |
| Military Hill Purchase Unit | U.S. Forest Service | 1,619 |
| Northern Highland American Legion State Forest | Wisconsin Department of Natural Resources | 1,557 |
| Northern Highland State Forest 5 | State Dept. of Natural Resources | 1,149 |
| Baraga Management Unit | Michigan DNR | 44 |
| Ontonagon Riverfront Park | Village of Ontonagon | 28 |
Species
No species records for this water in the files this site reads.
Historical July mean
The measured record behind every temperature band on this page: the mean of the daily means for July, at each gauge, over the years USGS has one.
| Gauge | July mean | July range | Julys |
|---|---|---|---|
| Rockland | 70.7 °F | 12.2 °F | 6 |
Hatches on this water
42 insects are recorded from the Upper Peninsula, 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 |
| 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 |
| 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 |
| Giant Black Stonefly (Salmonfly) Pteronarcys dorsata |
May–June | 50–62°F | #4–6 |
| Green Sedge Rhyacophila spp. |
May–August | 48–64°F | #12–16 |
And 28 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
11 named streams meet this one. Confluence miles are above the mouth; the longest twelve are listed.
- Middle Branch Ontonagon River 70.7 mi · RM 24.3
- East Branch Ontonagon River 59.1 mi · RM 24.3
- West Branch Ontonagon River 49.8 mi · RM 22.5
- Mill Creek 24.2 mi · RM 6.5
- Sucker Creek 19.5 mi · RM 17.0
- Sandstone Creek 6.2 mi · RM 23.6
- Plover Creek 3.8 mi · RM 23.4
- Rockland Creek 3.4 mi · RM 23.1
- Austin Creek 2.6 mi · RM 10.2
- Verrier Creek 2.5 mi · RM 16.5
- Irish Creek 1.7 mi · RM 14.1
Ontonagon River sits in HUC 8 04020102, the Ontonagon subbasin, and drains 1,344 square miles, Strahler order 8 at the mouth. 58 NHD reaches carry the name for 32.9 miles in total — more than the 24.3 miles of drawn mainstem, because NHD counts side channels and braids as their own reaches.
Other water nearby
The closest 6 rivers on this site, straight-line from the middle of this one — not drive time.