Most stocking advice comes down to "check your state's schedule." That works if you fish one state. If you fish more than one, or you are deciding where to drive in July, the more useful question is how the states differ from each other.
We hold 114,409 stocking records covering 2,878 named waters, published by four state agencies and normalized into one corpus: Washington Department of Fish and Wildlife, Utah Division of Wildlife Resources, New York State Department of Environmental Conservation, and Montana Fish, Wildlife & Parks. The records run from January 2000 to August 2026. This is what they show.
There are two stocking calendars, not one
Sort every record by the month it happened and the four states split cleanly into two groups.
| State | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Records |
|---|---|---|---|---|---|---|---|---|---|
| New York | 13% | 37% | 30% | 5% | 0% | 1% | 7% | 6% | 20,078 |
| Washington | 14% | 31% | 24% | 10% | 3% | 2% | 3% | 5% | 44,886 |
| Utah | 3% | 8% | 17% | 19% | 19% | 9% | 11% | 9% | 38,274 |
| Montana | 2% | 9% | 16% | 20% | 20% | 11% | 12% | 7% | 10,907 |
New York and Washington are spring-loaded. Both put roughly seven to eight records in ten into March through May, and both go quiet by midsummer. Utah and Montana spread their work from May through September, with the peak sitting a full two months later.
The gap is widest in July. New York records essentially no stocking that month. Montana and Utah are each running at their annual peak.
The pattern holds for catchable-size fish
A monthly split across all records could just be reflecting fry releases, which are timed to hatchery biology rather than to anglers. So we ran it again against catchable-size fish only, meaning anything six inches or longer. That is the fish you have a realistic chance of catching in the weeks after the truck leaves.
| State | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Catchable records |
|---|---|---|---|---|---|---|---|---|---|
| New York | 15% | 41% | 32% | 3% | 0% | 1% | 2% | 3% | 17,180 |
| Utah | 4% | 9% | 20% | 20% | 15% | 9% | 9% | 8% | 28,441 |
| Montana | 3% | 12% | 19% | 19% | 13% | 5% | 14% | 10% | 6,212 |
It gets sharper, not softer. New York does 88% of its catchable stocking in March through May and none at all in July. Utah is still stocking catchable fish in October at roughly the rate New York manages in March.
Montana has a wrinkle worth knowing: September (14%) outruns August (5%). If you are planning a Montana trip around fresh fish, early autumn is a better bet than late summer.
Washington is absent from this second table for a reason covered in the methodology below.
Counting fish tells you almost nothing
The corpus contains 6.18 billion fish. That number is true and nearly useless, because it counts a 0.3 inch walleye fry the same as a 10 inch rainbow trout.
Split New York's records by the size of what went in the water and the problem is obvious.
| Size band | Share of records | Share of fish | Average size |
|---|---|---|---|
| Fry, under 1 inch | 1% | 97% | 0.18 in |
| Fingerling, 1 to 6 inches | 13% | 1% | 3.96 in |
| Catchable, 6 inches and up | 86% | 1% | 10.08 in |
228 fry releases account for 97% of every fish New York put in the water. The individual releases are enormous: the state's walleye fry events run 150 million to 195 million fish at a time, at three tenths of an inch each. Meanwhile 17,180 separate catchable-size releases, the ones an angler would actually plan around, add up to about 1% of the fish count.
Utah and Montana are built differently. Utah puts 74% of its records into catchable-size fish, and those account for 44% of its total fish. Montana leans on fingerlings, which are 42% of its records and 47% of its fish, with catchables at 57% of records but only 19% of the count.
So a state that stocks ten times more fish than another may be stocking far fewer fish you can catch. Compare records, not totals.
The states stock different sized fish
Among the three states that publish a length, the average catchable release lands in a tight band, but the state-wide average does not.
| State | Average across all records | Average catchable release |
|---|---|---|
| Montana | 7.60 in | 11.06 in |
| Utah | 8.39 in | 10.27 in |
| New York | 9.15 in | 10.08 in |
Montana has the smallest overall average and the largest catchables. Both facts come from the same cause: Montana spends most of its records on fingerlings, so the small fish drag the state average down while the comparatively rare catchable release is a genuinely big fish.
One caution on trends. If you pool all four states and plot average size by year, the line climbs from about 8.0 inches in the late 2000s to 9.4 inches recently, which looks like a story about hatcheries growing bigger fish. It is not. New York joined the corpus in 2011 stocking at around 9.5 inches, and its arrival pulled the pooled average up. Within Montana the series is flat (7.60 to 7.56). Within Utah it moves less than two tenths of an inch. Nothing is getting bigger.
The 2020 gap
New York stocked 18 walleye events in 2020, a normal number, totaling 16.2 million fish. Every other year in the record runs between 132 million and 211 million. The event count held and the fish count fell by more than 90%.
The records say what happened, not why. We are not going to assert a cause from a stocking table.
The most-stocked waters
By count of catchable-size releases across the whole corpus:
| Water | Stocked by | Catchable releases |
|---|---|---|
| Strawberry Reservoir | Utah | 1,675 |
| Deer Creek Reservoir | Utah | 953 |
| Canyon Ferry Lake | Montana | 676 |
| Flaming Gorge Reservoir | Utah | 660 |
| Holter Reservoir | Montana | 602 |
| Lake Ontario | New York | 543 |
| West Branch Ausable River | New York | 526 |
Strawberry Reservoir alone carries 1,675 catchable releases and 31.6 million fish, which is more catchable releases than the next two waters combined.
The column names the agency doing the stocking rather than where the water sits, and for one entry those differ: Flaming Gorge Reservoir spans the Utah and Wyoming line, and Utah stocks it.
What this data is and is not
The records are published by four state agencies and assembled here without modification. Some limits worth stating plainly:
- Four states, not the country. Washington, Utah, New York and Montana. We hold a partial California feed of 264 records that is too thin to include, and nothing for the other 45 states. Nothing here describes national practice.
- Washington publishes no length. It reports fish per pound rather than inches, so all 44,886 of its records sit out every size comparison. Washington appears in the monthly tables and nowhere else.
- New York reports month precision only. Its dates are reliable to the month, which is all the monthly tables need, and it is excluded from anything finer.
- Species names are not standardized between states. "Rainbow trout", "Rainbow" and "Rainbow Trout" arrive as three separate values, one per agency. We map all of them onto a single species before counting. The corpus carries 83 raw agency names, which resolve to 55 species plus five entries that are not species at all ("Trout", "Panfish" and the like) and are left out rather than guessed at. Steelhead is kept separate from rainbow trout, and the named cutthroat subspecies are kept separate from generic cutthroat, because an angler would not accept one as the other.
- We group by the agency, the state reports group by the water. Everything above counts a record against the agency that published it. The linked state reports count it against the state the water sits in, so a handful of border waters land differently and the per-state totals there will not match this page exactly. Both add up to the same 114,409 records.
- Stocking does not mean fish are present. A truck came on a date. What survived, moved or got caught afterwards is not in any of these records.
Where to look next
Every state above has its own report with the underlying records, including species, hatchery where the state reports one, and the most recent events:
Each species in those reports has its own page, with the same month breakdown narrowed to one fish and the full list of waters it goes into. The ones this piece leans on:
- New York walleye, the fry program behind 97% of the state's fish count
- Utah rainbow trout and Washington rainbow trout, the same species on two different calendars
- Washington chinook salmon, stocked by the hundred-million at roughly three inches
- Montana westslope cutthroat trout, a subspecies stocked across 232 waters
To go the other direction and start from water rather than state, browse fishing spots by state and county. Waters we hold stocking records for show their full history on the spot page.
