Cooper Lake Fish Stocking
Kittitas County, Washington · 1995–2026 on record
According to Washington fish & wildlife agency, Cooper Lake was last stocked May 26, 2026 with Rainbow Trout. Cooper Lake has 38 stocking records on file, spanning 1995–2026, with about 155,023 fish stocked over that period.
When Cooper Lake is stocked
Cooper Lake is typically stocked in summer, most often in June — 16 stocking events in that peak month.
Angler's Field Guide
Fishing Tips & Stocking Guide for Cooper Lake
Practical advice on fish behavior, recommended tackle, and state regulations for anglers fishing in Kittitas County, Washington.
Post-Plant Behavior & Timing
Hatchery-raised fish are conditioned to pelleted feed and open raceways. Following a release into Cooper Lake, they typically congregate in schools near public access points, boat ramps, or inlets for the first 24 to 48 hours while adjusting to natural water conditions.
Since Cooper Lake was last stocked May 26, 2026, anglers visiting within 1 to 2 weeks of a reported event generally experience the highest activity before fish disperse into deeper cover.
State Regulations & Licensing
- •Fishing License: A valid Washington freshwater fishing license is required for anglers age 16 and older.Purchase Washington license online →
- •Official Rules & Limits: Bag limits, bait restrictions, and seasonal boundaries are set by Washington fish & wildlife agency.Official Washington regulations guidebook →
- •Ethical Conservation: Use barbless hooks and keep fish submerged in water during unhooking.Trout Thermal Advisory: When water temperatures rise above 68°F (20°C), released trout face severe mortality from thermal exhaustion. Target warmwater species or fish early in the morning when lakes and streams warm up.
Recommended Tackle & Presentations
Techniques tailored to the species stocked in Cooper Lake:
Stocked Trout Tactics
Use light 4–6 lb monofilament or fluorocarbon line. Float scented dough bait (PowerBait) 12–18" off bottom using a sliding slip-sinker rig with a size 14–16 treble hook. For active casting, throw 1/16 to 1/8 oz inline spinners (Panther Martin, Rooster Tail) or small spoons (Kastmaster) along drop-offs.
Rainbow Trout Profile Tips
The most commonly targeted stocked trout in the country, taken on bait, spinners, and flies alike; a common first fish for new anglers.
Cutthroat Trout Profile Tips
Known for being relatively easy to catch on dry flies, making it a favorite of western fly anglers; many subspecies are managed under catch-and-release rules to protect native populations.
Recommended Tackle for Cooper Lake
Field-tested tackle and presentations matched to the species stocked here.
Berkley PowerBait Floating Trout Dough
Hatchery-raised trout are conditioned to pelleted scents; scented dough floated 12–18 inches off bottom consistently triggers strikes.
Panther Martin Classic Teardrop Inline Spinner
The heavy convex blade spins instantly upon retrieval, sending vibration through the water that triggers aggressive reaction bites along drop-offs.
Sliding Sinker & Treble Hook Rigging Kit
Sliding egg sinkers allow cautious trout to run with bait without feeling line drag, while size 14–16 treble hooks keep dough bait securely pinned.
As an Amazon Associate, StockedWaters earns from qualifying purchases at no additional cost to you. Recommendations are chosen for hatchery-conditioned fish behavior and ethical rigging. We may receive a referral commission if you buy through these links. Read our editorial policy & standards.
Nearby stocked waters
Other stocked waters near Cooper Lake, freshest activity first.
Summit Chief Lake
7 miKittitas County · 1 species · 5 records
Last stocked July 2026
Thorp Lake
4 miKittitas County · 1 species · 30 records
Last stocked October 2025
Opal Lake
5 miKittitas County · 1 species · 6 records
Last stocked August 2025
Glacier Lake
6 miKittitas County · 1 species · 5 records
Last stocked October 2024
Diamond Lake
1 miKittitas County · 1 species · 9 records
Last stocked July 2023
Lila Lake
7 miKittitas County · 1 species · 8 records
Last stocked July 2023
Stocking history
Most recent stockings first. Dates shown at the precision the agency reported.
| Date | Species | Number | Source |
|---|---|---|---|
| May 26, 2026 | Rainbow Trout | 3,000 | Washington fish & wildlife agency |
| May 28, 2025 | Rainbow Trout | 3,000 | Washington fish & wildlife agency |
| May 28, 2024 | Rainbow Trout | 3,000 | Washington fish & wildlife agency |
| May 30, 2023 | Rainbow Trout | 3,000 | Washington fish & wildlife agency |
| June 8, 2022 | Rainbow Trout | 3,000 | Washington fish & wildlife agency |
| June 10, 2020 | Rainbow Trout | 2,544 | Washington fish & wildlife agency |
| May 20, 2020 | Rainbow Trout | 2,520 | Washington fish & wildlife agency |
| June 5, 2019 | Rainbow Trout | 2,496 | Washington fish & wildlife agency |
Show 30 more stocking records →
| Date | Species | Number | Source |
|---|---|---|---|
| May 20, 2019 | Rainbow Trout | 2,520 | Washington fish & wildlife agency |
| June 11, 2018 | Rainbow Trout | 2,750 | Washington fish & wildlife agency |
| May 21, 2018 | Rainbow Trout | 2,500 | Washington fish & wildlife agency |
| June 20, 2017 | Rainbow Trout | 283 | Washington fish & wildlife agency |
| June 6, 2017 | Rainbow Trout | 4,020 | Washington fish & wildlife agency |
| May 30, 2017 | Rainbow Trout | 3,500 | Washington fish & wildlife agency |
| June 2, 2016 | Rainbow Trout | 3,000 | Washington fish & wildlife agency |
| June 1, 2016 | Rainbow Trout | 417 | Washington fish & wildlife agency |
| May 18, 2016 | Rainbow Trout | 3,350 | Washington fish & wildlife agency |
| June 16, 2015 | Rainbow Trout | 250 | Washington fish & wildlife agency |
| June 2, 2015 | Rainbow Trout | 3,875 | Washington fish & wildlife agency |
| May 19, 2015 | Rainbow Trout | 500 | Washington fish & wildlife agency |
| May 4, 2015 | Rainbow Trout | 3,250 | Washington fish & wildlife agency |
| June 10, 2014 | Rainbow Trout | 2,750 | Washington fish & wildlife agency |
| May 28, 2014 | Rainbow Trout | 3,400 | Washington fish & wildlife agency |
| May 22, 2014 | Rainbow Trout | 750 | Washington fish & wildlife agency |
| June 12, 2013 | Rainbow Trout | 2,750 | Washington fish & wildlife agency |
| June 4, 2013 | Rainbow Trout | 2,137 | Washington fish & wildlife agency |
| May 22, 2013 | Rainbow Trout | 750 | Washington fish & wildlife agency |
| May 21, 2013 | Rainbow Trout | 2,970 | Washington fish & wildlife agency |
| June 18, 2012 | Rainbow Trout | 5,520 | Washington fish & wildlife agency |
| June 13, 2012 | Rainbow Trout | 2,640 | Washington fish & wildlife agency |
| June 12, 2012 | Rainbow Trout | 765 | Washington fish & wildlife agency |
| August 24, 2010 | Cutthroat Trout | 12,168 | Washington fish & wildlife agency |
| August 28, 2006 | Cutthroat Trout | 12,116 | Washington fish & wildlife agency |
| September 11, 2003 | Cutthroat Trout | 11,259 | Washington fish & wildlife agency |
| August 29, 2000 | Cutthroat Trout | 12,662 | Washington fish & wildlife agency |
| August 29, 2000 | Cutthroat Trout | 12,662 | Washington fish & wildlife agency |
| August 20, 1997 | Cutthroat Trout | 12,089 | Washington fish & wildlife agency |
| August 25, 1995 | Cutthroat Trout | 4,860 | Washington fish & wildlife agency |
The reporting agency did not include fish sizes for this water.
Frequently asked
When was Cooper Lake last stocked?
According to Washington fish & wildlife agency, Cooper Lake was last stocked May 26, 2026 with Rainbow Trout.
What fish species are stocked in Cooper Lake?
Cooper Lake is stocked with Rainbow Trout and Cutthroat Trout.
What time of year is Cooper Lake stocked?
Cooper Lake is typically stocked in summer, most often in June.
How often is Cooper Lake stocked?
Cooper Lake is stocked intermittently — 38 recorded stockings between 1995 and 2026.
How many fish have been stocked in Cooper Lake?
About 155,023 fish have been stocked in Cooper Lake across 38 recorded events since 1995, per Washington fish & wildlife agency.
Do you need a fishing license to fish Cooper Lake?
Yes, all anglers age 16 and older generally need a valid Washington freshwater fishing license. Always review current regulations from Washington fish & wildlife agency for site-specific rules, bag limits, or stamps.
How do you catch stocked trout in Cooper Lake?
Freshly stocked trout in Cooper Lake typically respond well to floating dough bait (such as PowerBait) floated 12–18 inches off bottom on light 4–6 lb leader, live nightcrawlers under a bobber, and small inline spinners or spoons retrieved along shorelines and drop-offs.