McMahon Lake
About McMahon Lake
McMahon Lake is an 187-acre lake near Credit River in Scott County, Minnesota. It reaches 14 feet at its deepest point, and has roughly 4.3 miles of shoreline. DNR surveys put average water clarity at about 5.3 feet.
Minnesota DNR fisheries surveys list 9 fish species here, including walleye, northern pike, largemouth bass, black crappie, bluegill, and yellow perch. The DNR has stocking records for the lake, so check the stocking report for the most recent species and year classes. The most recent fisheries survey on file dates to 2025.
There is one public boat launch (concrete surface) managed by the Minnesota DNR. The lake is listed as infested with Eurasian watermilfoil — clean, drain and dry your boat and gear before leaving. Ice typically goes out around March 25, based on 12 years of DNR ice-out records.
Plan Your Visit to McMahon Lake
- 187 acres, up to 14 feet deep, near Credit River
- 1 public boat launch (concrete) — managed by the Minnesota DNR
- Game fish on the DNR survey: walleye, northern pike, largemouth bass, black crappie, bluegill, and yellow perch
- Average water clarity around 5.3 feet
- Listed as infested with Eurasian watermilfoil — clean, drain and dry before you leave
Access & Fees
- Public access
- 1 public boat launch (concrete)
- Launch fee
- Free at DNR accesses
- Managed by
- Minnesota DNR
Conditions
- Surface area
- 187 acres
- Max depth
- 14 ft
- Shoreline
- 4.3 mi
- Water clarity
- 5.3 ft
- Shallows (under 15 ft)
- 158 acres
Rules & Regulations
- A Minnesota fishing license is required for anglers 16 and older
- Drain plugs must be out and all water drained before leaving any access; remove aquatic plants from boats and trailers
- Children under 10 must wear a life jacket on a boat that is underway
Facilities
- 1 public boat launch (concrete)
Best For
- Ice fishing
- Ice is never completely safe — check thickness yourself before walking or driving on any lake
Angler's Report
Minnesota DNR LakeFinder- Species on survey
- 9
- Game fish
- 6
- Stocked
- Yes
- Last DNR survey
- 2025
- Special regulations
- No
- Fishing pier
- No
- Ice fishing
- Yes
- Boat launch
- Yes
Fishing data: Minnesota Department of Natural Resources. Regulations change — confirm with the current DNR fishing regulations.
Ice-Out History
- Median ice-out
- March 25
- Years of record
- 12
- Earliest
- March 7, 2017
- Latest
- April 30, 2018
- Most recent
- March 26, 2026
See every lake on the ice-out tracker. Ice-out data: Minnesota DNR State Climatology Office.
Activities
Amenities
Fish Species
Plan your trip to McMahon Lake
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Nearby Lakes
Fish Lake
51 out of 100 Lake ScoreScott · Prior Lake176 acres
2.6 miles away
Cynthia Lake
25 out of 100 Lake ScoreScott · Prior196 acres
3.1 miles away
Cleary Lake
55 out of 100 Lake ScoreScott · Prior Lake145 acres
4.1 miles away
Spring Lake
51 out of 100 Lake ScoreScott · Prior Lake592 acres
5.4 miles away
Upper Prior Lake
54 out of 100 Lake ScoreScott · Grainwood386 acres
5.7 miles away
Cedar Lake
66 out of 100 Lake ScoreScott · New Prague793 acres
6.2 miles away
Frequently Asked Questions
Where is McMahon Lake?
McMahon Lake is in Scott County, Minnesota, near Credit River. It covers 187 acres and reaches 14 feet deep.
How big and how deep is McMahon Lake?
McMahon Lake covers 187 acres with about 4.3 miles of shoreline. Its maximum depth is 14 feet.
What fish can you catch at McMahon Lake?
Minnesota DNR surveys list Walleye, Northern Pike, Largemouth Bass, Black Crappie, Bluegill, and Yellow Perch. A Minnesota fishing license is required for anyone 16 and older.
Is there a public boat launch on McMahon Lake?
Yes. McMahon Lake has 1 public boat launch (concrete), managed by the Minnesota DNR. DNR public water accesses are free to use.
Can you swim at McMahon Lake?
There is no mapped public swim beach at McMahon Lake. Minnesota's public waters are open to swimming where you have legal access, but there are no lifeguards or water-quality monitoring away from designated beaches.
Is McMahon Lake stocked?
Yes. The Minnesota DNR has stocking records for McMahon Lake; species and numbers vary by year, so see the stocking report on DNR LakeFinder.
When does the ice go out on McMahon Lake?
The median ice-out date is March 25, from 12 years of Minnesota DNR records. The earliest on record is March 7, 2017 and the latest is April 30, 2018.
Does McMahon Lake have invasive species?
Yes. The DNR lists McMahon Lake as infested with Eurasian watermilfoil. State law requires you to clean off plants, pull the drain plug and drain all water before leaving the access.