Water & gauges
% of normal
Today's flow compared with the typical flow for this same date in past years.
“Normal” is the median daily flow for today's calendar date across the years the gauge has records. The median is the middle value: half of past years ran higher on this date and half ran lower. 100% means right at typical. Above about 150% the river is running high for the season (harder wading, often off-color). Below about 60% it's running low (clearer water, spookier fish).
Example “86% of normal” means the river is carrying a bit less water than usual for this date.
cfs (cubic feet per second)
How much water is moving down the river: the number of cubic feet of water passing a point every second.
One cubic foot is about 7.5 gallons, so 4,000 cfs means roughly 30,000 gallons flowing past the gauge every second. The number only means something compared with what's typical for that river, which is why we show it next to “% of normal.”
Example “Flow 4,210 cfs”
Clarity estimate
Our best guess at how clear the water is when the gauge has no clarity sensor, based on how fast the flow is changing.
A sharp rise in flow (25% or more in 24 hours) usually washes in sediment, so we show “Off-color?” A drop of 15% or more usually means the river is settling and clearing. Steady flow usually means normal clarity. It's an estimate, not a measurement.
Gauge height
The water level at the gauge, in feet, measured against a fixed marker. It isn't the depth of the river.
Gauge height goes up and down with the flow, but the number is only meaningful at that one gauge. For comparing conditions, flow (cfs) is more useful.
Off-color / stained
Water that's cloudy or tea-colored, usually from rain or rising flows.
Slightly off-color water can be good fishing because trout feel safer. When it's muddy, fish bigger, darker flies close to the bank where trout can still see them.
Provisional data
Recent readings that USGS hasn't reviewed yet. They're usually accurate but can be corrected later.
Sensors can be thrown off by ice, debris or equipment problems. USGS checks and approves the data later, so treat live numbers as a very good estimate, not a final record.
Tailwater
A river section just below a dam, where the dam controls the flow and often the temperature.
The lower Deschutes is a tailwater below the Pelton Round Butte dams, which is why its flows and temperatures are steadier than a free-flowing river's.
Turbidity (FNU)
How cloudy the water is, measured by a sensor. Higher numbers mean muddier water.
FNU (Formazin Nephelometric Units) measures how much light bounces off particles in the water. On this site: under 5 is clear, 5–15 tinted, 15–50 stained, over 50 muddy. Only some gauges have a turbidity sensor.
USGS gauge
A monitoring station run by the U.S. Geological Survey that measures the river automatically, usually every 15 minutes.
Gauges measure water level and calculate flow from it. Some also measure water temperature or turbidity. The Deschutes readings on this site come from the gauge near Madras (top of the lower river) and the gauge at Moody (near the mouth).
Water temperature
How warm the river is. It controls how active trout are and which insects hatch.
Rough guide for trout: below about 45°F they're sluggish; 45–55°F is cool and activity peaks midday; 55–65°F is prime; at 68°F and above trout get stressed, so fish early, land fish fast, or give them a rest.
Reading the river
Eddy
A spot where the current swirls back upstream, usually behind a rock or point. Food and insects pile up there.
Feeding lane
The narrow strip of current a trout watches for drifting food. Your fly needs to drift right down it.
Foam line
A trail of bubbles on the surface that shows where currents gather. Food collects there too, so fish do.
Pocket water
Small calm pockets behind and around rocks in fast water. Each one can hold a fish.
Riffle
Shallow, fast water broken by rocks, with a choppy surface. Where most river insects live.
Run
Deeper, steady water below a riffle, flowing at about walking speed. Classic holding water for trout and steelhead.
Seam
The line where fast water meets slower water. Trout rest in the slow side and grab food drifting by in the fast side.
Tailout
The shallow end of a pool or run, where the water speeds up before the next riffle.
Fish often sit in tailouts to feed, and spawning salmon and trout dig redds in tailout gravel.
Undercut bank
A bank the current has hollowed out underneath, giving fish shade and cover. Big brown trout love them.
Bugs & hatches
Adult cluster
Several tiny adult midges stuck together on the surface. A fly like a Griffith's Gnat imitates the clump.
Complete metamorphosis
Egg → larva → pupa → adult. Caddisflies and midges grow up this way.
Dun (subimago)
A freshly hatched mayfly drifting on the surface while its wings dry. Its dull, cloudy wings give it the name.
Emerger
An insect caught in the act of hatching at the surface. Helpless and easy for trout to eat.
Emerger flies sit low in or just under the surface film. They're often the answer when fish are rising but refusing regular dry flies.
Hatch
When lots of insects of one kind change from their underwater stage to winged adults at the same time.
During a hatch, trout often feed on just that one insect, so matching its size, color and stage matters. “Peak” on this site means the months when a hatch is usually strongest.
Incomplete metamorphosis
Egg → nymph → adult, with no pupa stage. Mayflies and stoneflies grow up this way.
Larva
The worm-like young stage of caddisflies and midges, living on the riverbed.
Match the hatch
Choosing a fly that looks like the insect trout are eating right now, in size, shape, color and stage.
Midge
Tiny two-winged flies (Chironomids) that hatch year-round. Often the main trout food in winter.
Nymph
The underwater young stage of mayflies and stoneflies. Trout eat nymphs far more often than adult insects.
Also the name for flies that imitate them, fished below the surface.
Pupa
The stage between larva and adult in caddis and midges. Pupae swim or float up to the surface to hatch.
Spinner (imago)
The mature adult mayfly. Spinners mate over the water, lay eggs and fall spent onto the surface with wings spread flat.
A “spinner fall” is when many die on the water at once, usually in the evening. Trout sip them quietly.
Terrestrial
A land insect, such as a grasshopper, ant or beetle, that falls or gets blown into the river.
Fish & life cycles
Adipose fin
The small fleshy fin on a salmon's or trout's back, between the dorsal fin and the tail. Hatcheries clip it off to mark their fish.
Example No adipose fin = hatchery fish (often keepable when open). Adipose fin present = wild fish (release it).
Alevin
A just-hatched fish that stays hidden in the gravel, living off the yolk sac attached to its belly.
Anadromous (sea-run)
Born in fresh water, grows up in the ocean, and returns to the river to spawn. Steelhead and salmon do this.
Fry
A tiny young fish that has used up its yolk sac and left the gravel to feed on its own.
Hatchery fish
A fish raised in a hatchery and released. They're usually marked by having the adipose fin clipped off.
Introduced
A species people brought into a river where it didn't live naturally, like brown trout in Oregon.
Juvenile
A young fish that's past the fry stage but not yet an adult.
Native
A species that lived in the river naturally, before people introduced anything.
Redd
A nest a female trout or salmon digs in the gravel to lay eggs. It looks like a clean, light-colored patch of gravel.
Don't wade through redds or fish to spawning fish. One step can crush thousands of eggs.
Smolt
A young salmon or steelhead whose body is changing to survive salt water, just as it heads downstream to the ocean.
Spawning
When fish lay and fertilize eggs. Most trout and salmon spawn in clean gravel.
Wild fish
A fish born naturally in the river, not raised in a hatchery. Wild fish usually have to be released.
Flies & techniques
Dead drift
Letting the fly float at exactly the speed of the current, like a real insect, with no pull from the line.
Drag
When the line pulls the fly faster or sideways compared with the current. Trout notice and refuse it.
Dry fly
A fly that floats on the surface, imitating an adult insect.
Dry-dropper
A floating dry fly with a small nymph hanging below it. The dry is both a fly and a strike indicator.
Euro nymphing (tight-line)
Nymphing without a float: a long rod, a thin line and heavy flies, feeling for strikes through the line.
Hook size (#)
How big a fly is. Bigger numbers mean smaller hooks: a #20 is tiny, a #4 is large.
Sizes run in even numbers. Above size 1, they switch to “aught” sizes that get bigger: 1/0, 2/0 and so on. On this site, “#14–16” means a size 14 or 16 hook.
Indicator
A small float on the leader that shows when a fish takes your nymph underwater.
Leader
The clear, tapered line between the fly line and the tippet, usually 7–12 feet long.
Mend
Flipping the floating line upstream (or down) after the cast so it doesn't drag the fly.
Nymphing
Fishing nymph flies near the bottom, usually dead-drifted. Often the most reliable way to catch trout.
Point fly / dropper
In a two-fly rig, the point fly is at the end of the line and the dropper hangs off the line above or below it.
Sink-tip
A fly line with a heavy section at the end that sinks, to get a swung fly down deep for steelhead and salmon.
Skated fly
A fly pulled across the surface so it leaves a small wake. Used for steelhead in low light.
Soft hackle
A simple wet fly with soft feathers that pulse in the current, imitating hatching insects.
Streamer
A larger fly that imitates a small fish, leech or crayfish, usually stripped or swung.
Strip
Pulling line in by hand in short tugs so the fly darts like a swimming baitfish.
Swing
Casting across the river and letting the current sweep the fly in an arc downstream. Classic for steelhead and soft hackles.
Tippet (5X, 6X…)
The thin last section of line the fly is tied to. Higher X numbers mean thinner and harder for fish to see.
Tube fly / shank fly
A large fly tied on a plastic tube or a hookless metal shank, with a separate hook attached. Common for steelhead and salmon.
Wet fly
A fly fished under the surface, usually swung across the current. Classic for steelhead.
Rules & seasons
Catch and release
Letting the fish go unharmed. Keep it in the water, remove the hook quickly, and let it swim off on its own.
Federally threatened
A species protected under the Endangered Species Act because it's at risk of becoming endangered. Don't target it.
ODFW
Oregon Department of Fish and Wildlife, the state agency that sets Oregon's fishing seasons and rules.
Peak / Active
On this site, “Peak” means the months something is usually at its best. “Active” means it's around, but not at its best.
Temporary rule / in-season change
A rule change ODFW makes during the season, such as an early closure, that overrides the printed regulations.
Salmon and steelhead seasons often change mid-year based on how many fish return, so always check ODFW's current rules before you go.