BirdTrout
Flag River, Wisconsin
14.1 mapped river miles, draining 33 square miles, in the Nemadji basin watershed. No gauge stands in it; the nearest is 12.9 miles away, and what this page knows about its temperature is Wisconsin DNR'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
The nearest gauge is 34.5 miles away, at Bad River Near Odanah, Wi — not a reading of this water, but of what the region is doing today. A closer gauge has stopped reporting — USGS carries no water-temperature series for it at all, so no number here comes from it.
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: 04026005.
The character of the water
The Flag is Class I and Class II water under Wisconsin DNR, managed as wild and as wild supplemented, and 15.0 of its 15.11 NHD miles are typed Cold — 99 per cent, the whole river and all of it the colder class. There is no gauge in it; the nearest is on the Bois Brule, 12.9 miles away. It runs 13.5 feet across at the median, fourth order, draining 33.14 square miles over 14.1 mapped miles of axis. Public ground is the striking part: 9.32 miles inside the Bayfield County Forest and 4.5 through the South Shore of Lake Superior fish and wildlife area, whose Flag River unit covers the same stretch, with a corner of the Chequamegon besides. The East Fork comes in at river mile 4.6.
Thermal classification
Wisconsin DNR's classification of this water, reach by reach. A class, not a temperature — no July mean, because none was measured here.
| Reach | Typed miles | Band | Wisconsin DNR type |
|---|---|---|---|
| RM 14.1–0.0 | 15.0 | cold | — |
Wisconsin DNR has classified 15.0 of the 15.1 miles NHD carries for this stream — 99% of it. Every typed reach carries the same class, cold. The untyped reaches are not warm water — they are water Wisconsin DNR's inventory does not reach, and the mile ranges above span only the reaches it does.
The lake run
The Flag River is a Lake Superior tributary with 13.0 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 Flag River →
Questions about this river
- Flag River fishing report — what it reads right now
- When to fish the Flag River — hatches, seasons and temperature
- How to get to the Flag River — access, parking and public land
- Flag River fishing regulations — season, size and gear by reach
Wisconsin DNR classification
Wisconsin DNR classifies this water as Class I and Class II. More than one class appears because the classification changes along the river. The thermal bar above shows where. The management tier on those reaches is wild, wild supplemented. This is a designation of the fishery, not the season and creel rules — those change yearly and live with the agency.
WDNR trout stream classification →
Public land on the river
5 units of public or open-access land touch this river, 1,134,300 acres in total. Acreage is the whole unit, not the part beside the water.
| Unit | Owner | Acres |
|---|---|---|
| Bayfield County Forest | county land | 178,260 |
| South Shore Lake Superior Fish | state natural-resources agency | 6,453 |
| South Shore Of Lake Superior Fish And Wildlife Area - Flag River Unit | state natural-resources agency | 1,053 |
| Chequamegon National Forest | U.S. Forest Service | 948,495 |
| South Shore Lake Superior Fish And 27 | state natural-resources agency | 39 |
Species
Wisconsin DNR designates this as trout water — Class I, Class II — without naming the species. No fish survey or stocking record for this water is in the files this site reads.
Hatches on this water
42 insects are recorded from northern Wisconsin, 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 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 |
| Light Cahill Maccaffertium ithaca |
May–July | 55–68°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
1 named stream meets this one. Confluence miles are above the mouth; the longest twelve are listed.
Flag River sits in HUC 8 04010301, the Nemadji basin, and drains 33 square miles, Strahler order 4 at the mouth. 37 NHD reaches carry the name for 15.1 miles in total — more than the 14.1 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.