Flat Lake Fish Stocking
Montana · 1973–2025 on record
According to Montana fish & wildlife agency, Flat Lake was last stocked June 5, 2025 with Rainbow Trout. Flat Lake has 79 stocking records on file, spanning 1973–2025, with about 160,740 fish stocked over that period.
When Flat Lake is stocked
Flat Lake is typically stocked in spring, most often in May — 30 stocking events in that peak month.
By species
Angler's Field Guide
Fishing Tips & Stocking Guide for Flat Lake
Practical advice on fish behavior, recommended tackle, and state regulations for anglers fishing in Montana.
Post-Plant Behavior & Timing
Hatchery-raised fish are conditioned to pelleted feed and open raceways. Following a release into Flat 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 Flat Lake was last stocked June 5, 2025, 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 Montana freshwater fishing license is required for anglers age 16 and older.Purchase Montana license online →
- •Official Rules & Limits: Bag limits, bait restrictions, and seasonal boundaries are set by Montana fish & wildlife agency.Official Montana 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 Flat 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.
Bass & Panfish Approach
Target visible structure such as docks, weed lines, and fallen trees. Small 1/32 to 1/16 oz jig heads with soft plastic grubs or live worms under a float work well for crappie and bluegill; soft plastic worms or spinnerbaits work well for bass.
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.
Northern Pike Profile Tips
Known for aggressive strikes on large spoons, spinnerbaits, and live bait; its sharp teeth call for wire leaders.
Recommended Tackle for Flat 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.
Gary Yamamoto 5-inch Custom Senko Stickbaits
The heavy salt-impregnated plastic produces a unique horizontal shimmy on the fall around weed beds, docks, and submerged timber.
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 Flat Lake, freshest activity first.
Fort Peck Trout Pond
4 mi1 species · 11 records
Last stocked October 2025
Home Run Pond
16 mi4 species · 85 records
Last stocked September 2025
Coe Campsite Pond #1
3 mi1 species · 62 records
Last stocked July 2020
Milk River
4 mi13 species · 325 records
Last stocked May 2014
Fort Peck Dredge Cuts
4 mi9 species · 77 records
Last stocked May 2013
Winter Harbor Pond
3 mi2 species · 7 records
Last stocked September 2009
Stocking history
Most recent stockings first. Dates shown at the precision the agency reported.
| Date | Species | Number | Size | Source |
|---|---|---|---|---|
| June 5, 2025 | Rainbow Trout | 1,000 | 7.03" | Montana fish & wildlife agency |
| June 27, 2024 | Rainbow Trout | 1,000 | 8.28" | Montana fish & wildlife agency |
| July 14, 2023 | Rainbow Trout | 1,055 | 6.7" | Montana fish & wildlife agency |
| May 24, 2022 | Rainbow Trout | 1,000 | 7.08" | Montana fish & wildlife agency |
| May 19, 2021 | Rainbow Trout | 1,000 | 6.83" | Montana fish & wildlife agency |
| May 26, 2020 | Rainbow Trout | 1,003 | 7.07" | Montana fish & wildlife agency |
| June 7, 2019 | Rainbow Trout | 1,000 | 7.33" | Montana fish & wildlife agency |
| June 13, 2018 | Rainbow Trout | 542 | 7.19" | Montana fish & wildlife agency |
Show 42 more stocking records →
| Date | Species | Number | Size | Source |
|---|---|---|---|---|
| October 31, 2017 | Rainbow Trout | 2,000 | 1.04" | Montana fish & wildlife agency |
| June 1, 2017 | Rainbow Trout | 1,006 | 6.87" | Montana fish & wildlife agency |
| May 18, 2016 | Rainbow Trout | 504 | 7.32" | Montana fish & wildlife agency |
| May 18, 2016 | Rainbow Trout | 503 | 7.32" | Montana fish & wildlife agency |
| May 11, 2015 | Rainbow Trout | 1,007 | 7.58" | Montana fish & wildlife agency |
| May 27, 2014 | Rainbow Trout | 1,005 | 7.51" | Montana fish & wildlife agency |
| June 18, 2013 | Rainbow Trout | 1,000 | 6.69" | Montana fish & wildlife agency |
| May 21, 2012 | Rainbow Trout | 1,017 | 7.02" | Montana fish & wildlife agency |
| June 28, 2011 | Rainbow Trout | 1,000 | 7.4" | Montana fish & wildlife agency |
| September 27, 2010 | Rainbow Trout | 452 | 7.02" | Montana fish & wildlife agency |
| May 4, 2006 | Rainbow Trout | 2,035 | 6.96" | Montana fish & wildlife agency |
| June 3, 2004 | Rainbow Trout | 1 | 5.9" | Montana fish & wildlife agency |
| June 3, 2004 | Rainbow Trout | 1,947 | 7.5" | Montana fish & wildlife agency |
| April 28, 2003 | Rainbow Trout | 2,072 | 6.85" | Montana fish & wildlife agency |
| May 30, 2001 | Rainbow Trout | 2,000 | 7" | Montana fish & wildlife agency |
| May 3, 2000 | Rainbow Trout | 2,002 | 7" | Montana fish & wildlife agency |
| May 3, 1999 | Rainbow Trout | 1,998 | 7.7" | Montana fish & wildlife agency |
| April 30, 1998 | Rainbow Trout | 1,300 | 7.3" | Montana fish & wildlife agency |
| April 30, 1998 | Rainbow Trout | 952 | 7.5" | Montana fish & wildlife agency |
| July 7, 1997 | Rainbow Trout | 800 | 8.3" | Montana fish & wildlife agency |
| May 4, 1997 | Rainbow Trout | 3,009 | 7.3" | Montana fish & wildlife agency |
| July 2, 1996 | Rainbow Trout | 1,988 | 9.4" | Montana fish & wildlife agency |
| April 29, 1996 | Rainbow Trout | 3,150 | 7.2" | Montana fish & wildlife agency |
| July 5, 1995 | Rainbow Trout | 1,000 | 9.5" | Montana fish & wildlife agency |
| April 24, 1995 | Rainbow Trout | 1,512 | 7.9" | Montana fish & wildlife agency |
| June 28, 1994 | Rainbow Trout | 1,500 | 9.2" | Montana fish & wildlife agency |
| May 3, 1994 | Rainbow Trout | 1,496 | 8.1" | Montana fish & wildlife agency |
| October 5, 1993 | Rainbow Trout | 1,498 | 6" | Montana fish & wildlife agency |
| July 1, 1993 | Rainbow Trout | 1,000 | 9.6" | Montana fish & wildlife agency |
| May 3, 1993 | Rainbow Trout | 1,508 | 7.7" | Montana fish & wildlife agency |
| May 18, 1990 | Northern Pike | 9,000 | 1.5" | Montana fish & wildlife agency |
| May 10, 1990 | Rainbow Trout | 1,813 | 7.8" | Montana fish & wildlife agency |
| May 9, 1989 | Rainbow Trout | 2,496 | 7.5" | Montana fish & wildlife agency |
| May 5, 1988 | Rainbow Trout | 2,483 | 7.9" | Montana fish & wildlife agency |
| May 6, 1987 | Rainbow Trout | 2,592 | 7.5" | Montana fish & wildlife agency |
| June 3, 1986 | Rainbow Trout | 2,283 | 8" | Montana fish & wildlife agency |
| May 29, 1985 | Rainbow Trout | 3,228 | 5" | Montana fish & wildlife agency |
| May 29, 1985 | Rainbow Trout | 2,213 | 7" | Montana fish & wildlife agency |
| May 17, 1985 | Fathead Minnow | 6,000 | 2" | Montana fish & wildlife agency |
| September 13, 1984 | Rainbow Trout | 3,780 | 8" | Montana fish & wildlife agency |
| July 15, 1982 | Largemouth Bass | 4,000 | 2" | Montana fish & wildlife agency |
| May 13, 1982 | Rainbow Trout | 4,002 | 8" | Montana fish & wildlife agency |
Showing 50 of 79 stocking records.
Frequently asked
When was Flat Lake last stocked?
According to Montana fish & wildlife agency, Flat Lake was last stocked June 5, 2025 with Rainbow Trout.
What fish species are stocked in Flat Lake?
Flat Lake is stocked with Rainbow Trout, Northern Pike, Fathead Minnow, Largemouth Bass, and Walleye.
What time of year is Flat Lake stocked?
Flat Lake is typically stocked in spring, most often in May.
How often is Flat Lake stocked?
Flat Lake has been stocked about 1 times a year — 79 recorded stockings between 1973 and 2025.
How many fish have been stocked in Flat Lake?
About 160,740 fish have been stocked in Flat Lake across 79 recorded events since 1973, per Montana fish & wildlife agency.
What size are the fish stocked in Flat Lake?
Fish stocked in Flat Lake average about 7.9 inches, based on the sizes the agency reported.
Do you need a fishing license to fish Flat Lake?
Yes, all anglers age 16 and older generally need a valid Montana freshwater fishing license. Always review current regulations from Montana fish & wildlife agency for site-specific rules, bag limits, or stamps.
How do you catch stocked trout in Flat Lake?
Freshly stocked trout in Flat 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.