Empty windows mean the cited source published no defensible dated harvest closure — a completed check, not a gap. Harvest is not assumed open. Bag, size and gear still apply.
What's in this reading
Five layers on this water
Open a layer to see the documented signals behind it and the unknowns it cannot close. Every layer reports what an agency published — none of it is an observation of the water today.
What the record says
boat launch and fishing pier
Fish River — access published by the managing agency
What this read cannot tell you
Same-day gate hours, fees and closures are set locally and are not mirrored here.
Facility condition (surface, dock presence, ADA status) is not tracked at record level.
Landowner boundaries adjacent to public corridors are outside this dataset.
Support is a hand-set weighting of how much documented material this layer rests on. It is not a probability and nothing here was measured.
Support is a hand-set weighting of how much documented material this layer rests on. It is not a probability and nothing here was measured.
Presence context only. This is never an expectation of catch, and carries no statement about timing, forage or activity. A note in brackets is the agency’s own condition on that fish and it outranks everything else on this page. Behaviour and presentation are the next instrument’s question — carry a species forward from the section below.
All of them at once
Decision
8 species, one temperature
Published bands for every species this record names. Put a temperature in to see where the water sits against them.
Inside the band The water is in the range this species was measured preferring.
Within two degrees A band endpoint is a laboratory summary rounded to a degree or two. Calling 71° comfortable and 72° out would give it a precision the source never claimed.
Tolerated, not preferred Outside the preference and inside the wider range the same source publishes — the faint bar behind each row. A great deal of fishing happens here.
Outside both Outside every published range. Still catchable — the band says where a fish is comfortable, not where it can be caught.
Nothing here ranks the species or scores the day. A fish outside its band is often exactly why people go, and turning a comfort range into a verdict would invent the one thing this catalogue exists not to invent. One band per species is a summer simplification — warmwater fish shift their preference ten degrees or more between winter and summer in the same laboratory. Species this record names with no reviewed band are absent from the drawing and listed under the plate below it.
Temperature
Where a reading would sit against the published bands
These are reviewed temperature bands for the species the agency documents here, each one carrying the source it came from. They describe the fish, not this water. Nothing on this page knows what Fish River is doing today — put a thermometer in it and the drawing will show you where that number lands.
Detail
Stays on this device. It is not saved, not synced and not sent anywhere — this instrument has no account to attach it to.
Temperature
Largemouth bass
Measured preference. A band for the species, not a forecast for Fish River.
Preferred 86–89.6°F The core. Where the reviewed record says this fish would rather be.
Active 60.6–90.5°F Feeding happens across this range. Wider than the core, and the edges are where a day gets difficult rather than impossible.
Edges Cold side from 50°F down. Warm or stressed from 93.2°F up. Outside the edges the fish is still there — it is just doing something other than feeding where you can reach it.
What you have No water temperature entered. This is the single measurement that moves the reading most, and a cheap thermometer beats a forecast every time.
What kind of number this is A measured preference. The fish chooses this range when it can, which is the kind of number worth planning around.
From the source The preferred band is a laboratory final preferendum (30–32 °C). Field preferenda observed in reservoirs ran cooler, 26.6–30.9 °C.
What this plate is telling you
What the edges are. Cold edge: lower growth limit. Warm edge: EPA short-term maximum. These are not one consistent quantity across species. A measured avoidance temperature is where fish were seen leaving; a water-quality maximum is a regulatory ceiling written to prevent a kill, and it sits well above the point a day gets difficult.
Source. Wismer & Christie 1987, Temperature Relationships of Great Lakes Fishes, GLFC Special Publication 87-3 (final preferendum from Coutant 1977a; growth data from EPA 1974 and Brown 1974). Read it.
Warmwater species swing their preference ten degrees or more between winter and summer in the same laboratory. One band per species is a summer simplification, and it is why the drawing shows a band rather than a line.
Altitude matters more here than people expect. The same water at 9,000 feet holds about a quarter less oxygen at saturation than it would at sea level. Leave it blank for sea level.
Oxygen
What this water could hold, against what the standard asks
Enter a water temperature above and the ceiling for this water appears on the curve.
Saturation curve The most oxygen fresh water can dissolve at each temperature, corrected for the elevation entered. Physics, not biology: it falls as the water warms.
Your reading No water temperature entered yet. The same thermometer that answers the temperature question answers this one.
Which column applies Chosen from the fish this record documents — . A record naming both trout and warmwater species takes the coldwater column, because a criterion is a floor and the stricter floor is the one protecting what is there.
Saturation is the most this water could hold if it were in equilibrium with the air. Real water sits below it — respiration, decomposition and a weed bed at four in the morning all take oxygen out — so the curve is an upper bound on a good day, never a measurement. Only a meter in the water tells you what is actually there.
What this plate is telling you
Why the curve falls. Gas solubility drops as temperature rises. Water at 80°F cannot hold what the same water held at 50°F, whatever lives in it. That is why a summer warm spell and a fish kill turn up in the same week, and why the cold layer at the bottom of a stratified lake — perfect temperature, no resupply from the surface since spring — can be the emptiest water in it.
What this is not. Not a reading, not a forecast, and not a statement about Fish River on any particular day. Agencies publish measured dissolved oxygen at many gauges — that number outranks everything on this drawing.
No band drawn for
Speckled trout — no reviewed source has been read for it yet. Absent rather than estimated.
Flounder — a family, not a species. The record has not said which one, and picking a member of it to fill the space would be inventing the answer.
Crappie — a family, not a species. The record has not said which one, and picking a member of it to fill the space would be inventing the answer.
Trout — a family, not a species. The record has not said which one, and picking a member of it to fill the space would be inventing the answer.
Bream — a family, not a species. The record has not said which one, and picking a member of it to fill the space would be inventing the answer.
Catfish — a family, not a species. The record has not said which one, and picking a member of it to fill the space would be inventing the answer.
Sturgeon — a family, not a species. The record has not said which one, and picking a member of it to fill the space would be inventing the answer.
Snapper — a family, not a species. The record has not said which one, and picking a member of it to fill the space would be inventing the answer.
The fish, not the water
Where these species hold, and when
Movement, habitat and spawning timing for the species this record names, from the agencies that survey them. Read alongside the temperature band above: the band gives the number, and these give the behaviour that makes the number worth knowing.
7 reviewed for Largemouth bass, Rainbow trout, Smallmouth bass, Walleye. Nothing here is a rule or a season — the regulation still comes from the managing agency, on the day.
Official guide
Largemouth bass — Fishes of Wisconsin
Wisconsin Department of Natural Resources
checked 2026-09-08
Puts numbers on the spawn: late April to early July, eggs laid at 62–65°F, nests on sand or gravel. Knowing the temperature rather than the date is what tells you whether the shallow pattern is on this week.
Why it made the list: Fetched 2026-09-08: page loads with Distribution, Spawning and Angling sections and states the 62–65°F egg-laying range verbatim.
A two-page federal profile giving the habitat types largemouth actually occupy and the thermal envelope in which they feed, with feeding cut-offs at 41°F and 98.6°F. Useful for ruling a water out rather than in.
Why it made the list: Fetched 2026-09-08: PDF renders, dated September 2023, USFWS branding, contains the 59–75°F spawning range and both feeding cut-offs.
Gives separate preferred bands for stream rainbows (54–66°F) and lake rainbows (45–64°F) against a 77°F upper tolerance, which is what lets you rule out water in midsummer. Spawning is a spring stream event, March to May, in fine gravel at the tail of a pool.
Why it made the list: Fetched 2026-09-08: page loads under Vermont Agency of Natural Resources branding with both temperature ranges and the March–May window.
Names the single most reliable habitat cue for the species — rock where crayfish are abundant, in medium to large streams and clearwater lakes. Spawning runs mid-May through June at 62–64°F, with records as low as 53°F.
Why it made the list: Fetched 2026-09-08: page loads and states the stream-and-clearwater-lake habitat text and the 62–64°F spawning temperature.
Smallmouth Bass Movement and Habitat Use in the Upper Mississippi River
Minnesota Department of Natural Resources
checked 2026-09-08
A radio-telemetry study, so the movement is measured rather than asserted: fall migrations up to 27 km to slack-water wintering areas, spring migrations up to 29 km back, and a return to the same summer spots. Habitat use breaks down as eddies 33%, pools 27%, runs 25%.
Why it made the list: Fetched 2026-09-08: PDF loads in full, Eric R. Altena, MN DNR, April 2003, report F-29-R(P)-22 Study 4 Job 621, containing the migration distances and habitat percentages.
Explains the eye — the tapetum lucidum that lets walleye feed in low light and stained water — and therefore why they push shallow at dawn and dusk and drop into depth or shade as light rises. Spawning peaks at 42–50°F over shallow rock and gravel.
Why it made the list: Fetched 2026-09-08: page loads on dnr.state.mn.us with the tapetum lucidum explanation, the dawn-and-dusk feeding line and the 42–50°F spawning peak.
Takes apart the assumption that walleye live on deep rock and walks through the range of structure they actually use through a season. It is about where the fish are, not what to throw at them.
Why it made the list: Fetched 2026-09-08: page loads with a video player embed and a description contrasting early In-Fisherman findings on walleye location with current understanding.
Moving water. The read is about current first and depth second.
A river hands you the fish's problem for free: it has to hold somewhere it can eat without swimming hard all day. Find the places where fast water and slow water meet, and you have found where to start on most rivers, including ones you have never seen before.
Craft, not observation — this is the standing read for a river. It holds no clarity, temperature, level, flow, tide or hatch for this water today, and it does not name a spot.
Detail
Water section
Moving water. The read is about current first and depth second.
A section through water of this class, near side on the left. It is craft, not a survey of Fish River — the shape of this particular bank is yours to read when you get there.
1Current seams A fish can sit in the slow side and let the fast side deliver food. It is the cheapest lie on the river, so it is usually the first one taken. — likely.
2Riffle, run, pool, tailout Each part holds fish for a different reason and at a different time of day. The run is the workhorse; the tailout and the head of the pool are the feeding stations. — likely.
3Outside bends and cut banks Depth, shade and an overhead lid in one place. On a bright day or in low water this is where the better fish are. — likely.
4Eddies and current breaks A resting lie right beside a feeding lane. Fish move between the two rather than holding in the push all day. — worth checking.
5Tributary mouths and confluences A concentration point that works in almost every season, and a refuge when the main stem is high, warm or coloured. — worth checking.
6Wood, undercuts and sweepers Overhead cover plus a current break. It is also the hardest water to fish cleanly, which is exactly why it holds fish. — worth checking.
7Depth changes and shelves Fish use depth changes as travel routes and as ambush points. A one-foot change can matter as much as a ten-foot one. — worth checking.
What this plate is telling you
Solid zones are features this class of water nearly always has. Dashed ones are the subtler reads — present often enough to look for, not often enough to assume.
Nothing here is an observation of today. No gauge reading, no clarity, no temperature and no fish went into this drawing. It is the same standing craft an angler carries between waters, and the water in front of you outranks all of it.
Plan view · where along the water
A reach of river, seen from above
One meander with the water moving left to right. Every river you will ever stand on is some version of this repeated — riffle, run, pool, tailout, and the bend that builds all four. It is a schematic of this class of water, not a survey of Fish River — the shape of that particular shore is yours to read when you get there.
Nothing on this reach is doing anything unusual. That is a normal day, and normal days are read by walking rather than by diagram. Set a wind, a water state or a tide and the picture will move.
Water state
Tap a marked zone on the picture, or choose one by name above, for what it is, why fish relate to it, and how to find it standing there with no map. Nothing here says a fish is present — it says the physical reason that piece of water is worth a cast, and under which conditions that reason gets stronger or stops applying.
Decision flow
Four questions before the first cast
The drawing names features. This is the order that keeps them from becoming a scavenger hunt. Start with the force moving the water, find the shape that interrupts it, ask what changed, then verify the part the diagram cannot know today.
Where is the current doing less work?
Look for
Inside bend, eddy, bank edge, pocket behind structure.
Why it matters
A fish can hold close to the food lane without spending the same energy as the main flow.
Where does fast water touch slow water?
Look for
Bubble line, surface crease, edge of a riffle or tributary colour line.
Why it matters
That boundary is a feeding lane worth testing before the featureless middle.
Did the river move since the last read?
Look for
Rising colour, exposed gravel, new flooded edge, generation change.
Why it matters
The useful edge can move metres. The old answer may be physically gone.
When the water changes
It rained. They ran the dam. The wind swung.
Pick what actually happened. Nothing here reads a gauge — you supply the event, from your own eyes or the agency's page, and this says what it does to water of this class.
Still craft, not observation — this is what these changes do to a river. It does not know whether any of them happened here, and it never will. The agency's page and your own eyes are the only things that do.
What this record changes about the read
Cold-water species are documented here. Read for oxygen and temperature as much as for cover: broken water, inflows, shade and depth.
Current
Current seams
What it is
The line where fast water runs against slow — visible as a crease, a change in surface texture, or a trailing foam line.
Why fish hold there
A fish can sit in the slow side and let the fast side deliver food. It is the cheapest lie on the river, so it is usually the first one taken.
How to find it
Stand back and look across, not down. Seams show as a long straight edge in an otherwise broken surface, often below a riffle or beside an obstruction.
Depth
Riffle, run, pool, tailout
What it is
A river repeats the same four-part sequence: broken shallow riffle, deeper walking-pace run, slow deep pool, then a shallowing tailout at the pool's exit.
Why fish hold there
Each part holds fish for a different reason and at a different time of day. The run is the workhorse; the tailout and the head of the pool are the feeding stations.
How to find it
Walk the bank and name the parts before you fish anything. If you cannot name where you are standing, you are guessing.
Depth
Outside bends and cut banks
What it is
On a bend the current is thrown to the outside, which scours it deep and often undercuts the bank; the inside builds a shallow gravel point bar.
Why fish hold there
Depth, shade and an overhead lid in one place. On a bright day or in low water this is where the better fish are.
How to find it
Follow the bend with your eye: darker water and a hard bank line on the outside, pale gravel on the inside.
Current
Eddies and current breaks
What it is
Slack or reversed water behind a boulder, bridge pier, log jam, wing dam or point of bank.
Why fish hold there
A resting lie right beside a feeding lane. Fish move between the two rather than holding in the push all day.
How to find it
Look for the pillow of raised water upstream of the obstruction and the smooth pocket behind it. Fish the pillow as well as the pocket.
Edges
Tributary mouths and confluences
What it is
Where a creek or a side channel enters, bringing different temperature, clarity, oxygen and food.
Why fish hold there
A concentration point that works in almost every season, and a refuge when the main stem is high, warm or coloured.
How to find it
The colour or texture line downstream of the junction shows how far the incoming water carries before it mixes. Work that line.
Cover
Wood, undercuts and sweepers
What it is
Fallen trees, root wads, sweepers hanging into the flow and undercut banks held together by roots.
Why fish hold there
Overhead cover plus a current break. It is also the hardest water to fish cleanly, which is exactly why it holds fish.
How to find it
Read the current going into the wood, not the wood itself — the fish sits where the flow is broken, usually on the upstream or downstream edge, not in the tangle.
Depth
Depth changes and shelves
What it is
The lip at the head of a pool, a mid-river shelf, a gravel-to-bedrock transition, a dredged slot.
Why fish hold there
Fish use depth changes as travel routes and as ambush points. A one-foot change can matter as much as a ten-foot one.
How to find it
Polarised glasses and a low sun angle. Colour change on the bottom is the cheapest depth sounder there is.
3 further cues for this water class are held at a higher detail setting.
Watch · verify · keep reading
Useful instruction outside this app
These links teach transferable mechanics. They are not sources for today’s access, rules, weather or safety. A video can explain what a current seam is; it cannot tell you whether the ramp at a named water is open this morning.
15 reviewed for this class of water. Every link was opened on the date beside it — a dead link is a defect here, not a footnote, and a scheduled job re-checks them.
Agency and official references
Published by the bodies that measure and manage the water. These are the stable ones, and the ones to cite.
Official guide
What Are Stream Features? Riffle to Glide
Ausable River Association
checked 2026-09-08
Defines riffle, run, pool and glide by what causes them — substrate size, gradient, position on a meander — rather than by how they look, and shows how the sequence repeats down a reach. It gives you the vocabulary before you start deciding where to fish.
U.S. Geological Survey, Water Resources Mission Area
checked 2026-09-08
What the gauges actually record — stage every fifteen minutes, converted to discharge through a rating curve built for that one site — and why some sites will never show you a flow number at all. This is what makes a gauge page legible rather than a squiggly line.
The short version of gage height against discharge, and of gage datum — the per-site reference point that means 4.2 feet at one gauge has no relationship to 4.2 feet at another. Read it before you compare two gauges or treat a stage number as a depth.
Why water temperature drives dissolved oxygen, and how a lake separates into layers through the season, with temperature-depth profiles from a real lake across May to October. The general-principles piece behind every seasonal temperature question in this app.
A working example of what a Corps district publishes: pool and tailwater elevations, storage, hourly project data and proposed generation schedules. Use it as the template for finding the equivalent page for whichever district operates your reservoir — every district runs one.
Daily reservoir and river operations across the five Reclamation regions, including the hydromet systems and the RISE portal. Reclamation rather than the Corps operates most western reservoirs, so this is where those levels and releases live.
The three stages of cold water immersion, and the part most anglers have wrong: cold shock can be triggered by water as warm as 77°F, so a mild air temperature tells you nothing. Read it before spring wading and before any early-season boat or shore trip.
EPA's hub, including the route to current state, tribal and local advisories. Advisories are issued locally rather than federally, so this is how you find out whether one specific water is under one right now.
What a bloom looks like in the water — foam, scum, a spilled-paint surface — and the exposure routes for people and for dogs. The practical rule is to stay out of discoloured or foul-smelling water and check the local advisory first.
Clean, drain, dry as an actual procedure rather than a slogan: rinse the hull and gear, flush the motor, drain bilge and livewell before you leave the access, dry five days or towel down, bin unused bait. Written to be done every water, every time.
A good model of how a state regulations system is built: an annual pamphlet of statewide rules, water-specific exceptions that override them, and an emergency rule feed that supersedes the printed pamphlet mid-season. That three-part shape is near-universal, so it teaches you what to go looking for in your own state.
A state identification index covering the 162 species in Minnesota waters, with a downloadable poster and a fish-families guide. Most agencies publish an equivalent, and the agency version is the one whose names match the regulations booklet.
Craft, taught by people who fish. Chosen for the instruction and the publisher’s track record, not because a recommendation algorithm surfaced them — the observed audience numbers are on each card so you can weigh that yourself.
Video
Chapter Eight: Reading The Water
Orvis Learning Center
checked 2026-09-08
Twelve short lessons on current, cover, pool tails, big rivers, pocket water, floods and droughts. The examples are trout-heavy; the current-reading mechanics travel farther than that.
Why it made the list: Re-verified 2026-09-08: page loads, all twelve segments present. Established instructional series with the whole chapter in one place.
A compact worked example of depth, overhead cover and food supply in an ordinary straight reach. Useful after the schematic because it shows the same questions on real water.
Why it made the list: 6,801 views and 142 likes observed 2026-09-08; The Orvis Company channel, 112K subscribers, published 2020.
You have answered where and what kind of water. Each instrument below answers the next question in the same workflow, and each link carries this record's water class, documented species, standing read, access position and declared job with it. Nothing is posted automatically, and no coordinates or private water travel in the handoff.
Narrow the handoff to one documented species (optional)
Species context is what the agency published for this water. It is never a statement that a fish is present today, or catchable.
01WaterYou are here
Field Sense Navigator — which water, what kind, what to look for and what still has to be checked today.