Diamond Lake Fishing
A 1,042-acre Michigan lake in Cass County.
Pick for walleyePiscifun Viper X spinning reel50% OFFSale $39.99 Photo of St. Joseph River: Paul Sableman from St. Louis, MO, CC BY 2.0
Diamond Lake: size, place and fish
Cass County holds Diamond Lake, a lake of 1,042 acres. The nearest Census place is Cassopolis, roughly 2 miles from the shore point. Management unit: Southern Lake Michigan; peninsula: Lower Peninsula. Its water heads toward the Southeastern Lake Michigan basin, in the Southern Michigan/Northern Indiana Drift Plains ecoregion.
MDNR records name walleye. You can launch at 1 public launch. A 2023 satellite estimate shows about 8.4 feet of visibility.
For the walleye herePiscifun AlumiX spinning reel46% OFFSale $64.99 What swims in Diamond Lake
Each fish below has an MDNR record tied to Diamond Lake.
How often surveys found each fish at Diamond Lake
| Species | Atlas records | Years |
|---|---|---|
| Black crappie | 1 | 1958 |
| Blacknose shiner | 1 | 1958 |
| Bluegill | 1 | 1958 |
| Bluntnose minnow | 1 | 1958 |
| Bowfin | 1 | 1958 |
| Brook silverside | 1 | 1958 |
| Brown bullhead | 1 | 1958 |
| Golden shiner | 1 | 1958 |
| Johnny darter | 1 | 1958 |
| Largemouth bass | 1 | 1958 |
| Longnose gar | 1 | 1958 |
| Mimic shiner | 1 | 1958 |
| Northern longear sunfish | 1 | 1958 |
| Northern pike | 1 | 1958 |
MDNR Fish Atlas and Family Friendly Fishing lists, MDNR stocking table, checked October 2026. Older collections are history, not a current survey.
Launch sites at Diamond Lake
- Diamond Lake Boat Access near Cassopolis2 lanes, 60 trailer spaces, courtesy pier, toilet, Recreation Passport; Cassopolis Field Office
Ramps within reach of Diamond Lake
- Stone Lake Boat AccessStone Lake, 2 miles west
- Paradise Lake Boat Access near VandaliaParadise Lake, 3 miles east
- Curtis Lake Boat AccessCurtis Lake, 4 miles southeast
- Donnell Lake Boat AccessDonnell Lake, 4 miles east
- Chain Lake Boat AccessChain Lake, 5 miles southeast
- Juno Lake Boat AccessJuno Lake, 6 miles south
MDNR Parks and Recreation boat access sites and MDNR fishing sites, checked October 2026.
The color and clarity of Diamond Lake
EGLE derives the Diamond Lake readings from Landsat, July through September.
Algae, measured as chlorophyll a, ran 3.99 micrograms per liter in 2023.
EGLE Michigan Inland Lakes Water Clarity layer (Landsat, July to September), checked October 2026. Depth is not published here: the layer depth fields are unreliable.
Season dates at Diamond Lake
| Species | Limit | Season |
|---|---|---|
| Largemouth and smallmouth bass | 5 in any combination; minimum 14 inches | Possession: Sat. before Memorial Day – Dec. 31; catch-and-immediate-release open all year |
| Walleye (Lower Peninsula) | 5; minimum 15 inches | Last Sat. in April – March 15 |
| Northern pike (Lower Peninsula) | 2; minimum 24 inches | Last Sat. in April – March 15 |
| Muskellunge | Only 1 per angler per license year (April 1 – March 31); mandatory harvest registration within 24 hours; minimum 42 inches (46, 50 or 38 inches on listed waters) | Possession: 1st Sat. in June – March 15; catch-and-immediate-release open all year |
| Yellow perch | 25 | Open all year |
| Sunfish and crappie | 25 in any combination of the listed species | Open all year |
| Channel catfish | 10; minimum 12 inches | Open all year |
| Flathead catfish | 5; minimum 15 inches | Open all year |
| White bass | 10 | Open all year |
| Cisco and whitefish | 5 in any combination | Open all year |
| Burbot | 5 | Open all year |
| Trout in unclassified lakes | 5, no more than 3 of which may be 15 inches or greater; minimum 8 inches | Open all year |
The table gives the statewide inland limits Diamond Lake falls under on the Lower Peninsula.
2026 Michigan Fishing Regulations (April 1, 2026 to March 31, 2027), statewide tables and county exceptions, checked October 2026.
MDNR plants at Diamond Lake
Between 2026 and 2026, 1 recorded plants put 46,637 fish into Diamond Lake; walleye lead the list.
| Date | Species | Strain | Avg length | Number |
|---|---|---|---|---|
| June 2, 2026 | Walleye | Muskegon | 3.5 in | 46,637 |
MDNR Fish Stocking Report table, January 2024 to October 2026. Michigan stocking.
Club and trail events on Diamond Lake
See the Diamond Lake tournament page for organizers and weights.
Diamond Lake compared with close lakes
| Lake | Distance | Acres | Launches | Clarity ft | Fish listed |
|---|---|---|---|---|---|
| Diamond Lake | 1,042 | 1 | 8.4 | 1 | |
| Stone Lake, Cass County | 2 miles west | 157 | 1 | 13.9 | 0 |
| Puterbaugh Lake | 2 miles south | 44 | 0 | 12.7 | 0 |
| Paradise Lake, Cass County | 4 miles east | 186 | 1 | 11 | 0 |
| Curtis Lake, Cass County | 4 miles southeast | 28 | 1 | 8.7 | 0 |
| Donnell Lake | 5 miles east | 247 | 1 | 9.1 | 0 |
EGLE inland lake layer, MDNR access sites and Fish Atlas.
A short drive from Diamond Lake
Lakes in the same corner as Diamond Lake
- Stone Lake, Cass County2 miles west
- Puterbaugh Lake2 miles south
- Paradise Lake, Cass County4 miles east
- Curtis Lake, Cass County4 miles southeast
- Donnell Lake5 miles east
Shops to stop at on the way to Diamond Lake
- Clear H2O Tacklebait and tackle shop, Edwardsburg, 7 miles
- Guntle's Outdoor Outfittersbait and tackle shop, Dowagiac, 9 miles
- Hall's Bait & Tacklebait and tackle shop, Union, 10 miles
- The Trading Postbait and tackle shop, Edwardsburg, 10 miles
- Eagle Bait & Tackle Sports Storebait and tackle shop, Edwardsburg, 11 miles
- Lake Effect Marinamarina, Union, 11 miles
Guides that list Diamond Lake
- Gold Coast Fishing Co.charter, Saint Joseph, (269) 548-7304
- Golden Eye Charterscharter, Berrien Center, (269) 471-7162
- Sea Hawk Sport Fishing Charterscharter, Stevensville, (269) 428-9866
- Silver King Sportfishing Chartercharter, Saint Joseph, (269) 983-7816
Base camps for Diamond Lake
- Cassopolis2 miles
- Vandalia4 miles
- Dowagiac9 miles
Counties that Diamond Lake spans
- Cass Countyseat: Cassopolis
Piscifun gear picked for Diamond Lake
.jpg){kind=link}
Piscifun and Amazon links are affiliate links; the site earns a commission on qualifying purchases.
Species to expect at Diamond Lake
Photo: United States Fish and Wildlife Services, Public domain
Photo: George Chernilevsky, CC BY-SA 4.0
Photo: USFWSmidwest, Public domain
.jpg){kind=link}
Photo: Nick Loveland, CC0
Things to settle before fishing Diamond Lake
Which part of Michigan holds Diamond Lake?
Its shore is in Cass County, Southern Lake Michigan Management Unit, about 2 miles from Cassopolis.
What size is Diamond Lake?
1,042 acres of surface water.
Does Diamond Lake have a public boat launch?
MDNR maps 1 public launch; Diamond Lake Boat Access near Cassopolis is a good start.
What swims in Diamond Lake?
walleye, per MDNR records.
Which MDNR rules govern Diamond Lake?
Walleye (Lower Peninsula): 5; minimum 15 inches; season Last Sat. in April – March 15.
Can a visitor fish Diamond Lake on a Michigan license?
Anglers 17 and older carry a Michigan all-species fishing license: $26 a year for residents, $76 for nonresidents, $11 for seniors or $10 for one day.
Does Diamond Lake run clear or murky?
Summer 2023 imagery: about 8.4 feet.
Who sells bait nearest Diamond Lake?
Clear H2O Tackle sits about 7 miles from the lake.
Is Diamond Lake stocked?
In 2026 the MDNR planted 46,637 walleye.
Pick a weekend for Diamond Lake
The license page holds every Michigan fee and season.