BirdTrout
Little Sugar River, Wisconsin
17.4 mapped river miles, draining 127 square miles, in the Sugar basin watershed. No gauge stands in it; the nearest is 11.8 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 11.8 miles away, at Sugar River Near Verona, Wi — not a reading of this water, but of what the region is doing today.
The character of the water
The Little Sugar is Class I water under Wisconsin DNR, managed as wild, with 9.7 of its 32.46 NHD miles typed Cold — 30 per cent, and nothing classed otherwise. The wild designation covers the river; the thermal class covers under a third of it. There is no gauge in it and no measured temperature. The channel is 18.4 feet across at the median, fifth order, draining 126.69 square miles over the 17.4 miles of axis mapped. Public ground is three pieces and one of them does the work: 1.28 miles inside the Sugar River State Trail corridor, with the Albany Wildlife Area and an extensive habitat parcel adding about a seventh of a mile each despite covering thousands of acres apiece. Ward Creek, Legler School Branch and Spring Valley Creek come in between river miles 5.3 and 8.5.
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 14.1–4.2 | 9.7 | cold | — |
Wisconsin DNR has classified 9.7 of the 32 miles NHD carries for this stream — 30% 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.
Questions about this river
- Little Sugar River fishing report — what it reads right now
- When to fish the Little Sugar River — hatches, seasons and temperature
- How to get to the Little Sugar River — access, parking and public land
- Little Sugar River fishing regulations — season, size and gear by reach
- Is the Little Sugar River good for brown trout?
- Is the Little Sugar River good for rainbow trout?
Wisconsin DNR classification
Wisconsin DNR classifies this water as Class I. The management tier on those reaches is wild. 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
3 units of public or open-access land touch this river, 10,481 acres in total. Acreage is the whole unit, not the part beside the water.
| Unit | Owner | Acres |
|---|---|---|
| Sugar River State Trail | state natural-resources agency | 245 |
| Extensive Wl Habitat - Public Hunting Ground | county land | 8,286 |
| Albany Wildlife Area | state natural-resources agency | 1,949 |
Species
WDNR has stocked brown trout into this water 10 times between 2015 and 2023. That is a stocking record rather than a survey — it says the fish were put in, not that a survey has found them since.
WDNR has stocked rainbow trout into this water 9 times between 2016 and 2025. That is a stocking record rather than a survey — it says the fish were put in, not that a survey has found them since.
Hatches on this water
51 insects are recorded from the Wisconsin driftless, 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 |
| Hendrickson Ephemerella subvaria |
April–May | 45–58°F | #12–14 |
| Little Black Caddis Chimarra atterima |
April–May | 46–58°F | #16–20 |
| Caterpillar Lepidoptera larvae |
May–September | 55–75°F | #8–14 |
| Crayfish Orconectes spp. |
May–October | 55–78°F | #4–8 |
| Inchworm Geometridae |
May–June | 50–68°F | #12–16 |
| Light Cahill Maccaffertium ithaca |
May–July | 55–68°F | #12–16 |
And 37 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
3 named streams meet this one. Confluence miles are above the mouth; the longest twelve are listed.
Little Sugar River sits in HUC 8 07090004, the Sugar basin, and drains 127 square miles, Strahler order 5 at the mouth. 74 NHD reaches carry the name for 32.5 miles in total — more than the 17.4 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.