Green

Green Lake is an 832-acre lake located eight miles east of Princeton and 10 miles west of Cambridge, in west-central Isanti County, and is within the Rum River Watershed. The lake has a maximum depth of 28 feet and an average depth of 21 feet. It is 43% littoral (15 feet or less, 357 acres). Water clarity is generally low due to frequent algae blooms, with Secchi depths between 2 and 4 feet. There are three small named inlets: one in the northcentral (North Brook), one in the northeast adjacent to the public access (Bratlund Brook), and one in the southwest (Wyanett Creek). There is one larger outlet in the southeast (Green Brook Creek) that flows into the Rum River three miles downstream of the lake outlet. Due to high nutrient availability and 43% of the lake being less than 15 feet, aquatic vegetation is plentiful and has been sampled to depths of 10 feet. Recent plant surveys indicate a very diverse plant community. Eurasian Watermilfoil, a non-native species, has been present since 2000, and Curlyleaf Pondweed has been present since 1971. Substrates are primarily sand, with some gravel and rubble. The lake is highly developed with approximately 175 homes (38/shoreline mile). A paved, state-owned public access is located on the northeast shore that accommodates 20 vehicles with trailers. There have been a total of 16 fish surveys completed to monitor for changes in species composition, number, and length distribution. Primarily management species are Walleye and Northern Pike, while secondary species include Black Crappie and Largemouth Bass. Angers fishing Green Lake can expect moderate numbers of quality sized Walleye and Northern Pike with high numbers of average sized Black Crappie and Largemouth Bass. Walleyes were stocked initially in 1949 and have been sampled in all 16 surveys, which were initiated in 1949. In 2025, the gill net catch rate was 5.9/net, which compares to the average of 6.3/net. Catch rates have varied between 0.1/net in 1949 to 35.8/net in 1957. The 53 Walleye sampled ranged from 7.6 to 24.8 inches and had an average length of 17.1 inches. Walleyes over 25 inches have been sampled in the past 8 consecutive surveys and 12 of the 16 surveys. Catch rates for fingerling stocked Walleye year classes have resulted in more consistent gill net catch rates, indicating the current stocking plan is providing a stable Walleye fishery. A total of 36 Northern Pike were sampled in gill nets in 2025 which resulted in a catch rate of 4.0/net. Gill net catch rates have varied from 0.1/net in 1949 to 6.0/net in 1976 and have averaged 3.8/net. Catch rates have never exceeded 7.5/net, which is good. Research indicates pike catch rates over 7.5/net are undesirable, as they are usually associated with higher density populations having poor size structure and slow growth. Higher pike densities can also have detrimental effects on stocked Walleye survival and perch populations. Perch are often a primary prey species. The pike sampled ranged from 20.0 to 33.1 inches and averaged 24.7 inches. The average length of pike sampled by gill nets in 2021 was similar at 25.1 inches. Pike over 28 inches have been sampled in 7 of the past 8 surveys, while pike over 34 inches were sampled in one. The largest pike ever sampled was a 43.3-inch fish in 2016. Age information indicates annual natural recruitment occurs consistently. Overall, anglers that fish Green Lake for pike can expect to catch moderate numbers of quality sized pike with a chance of catching one over 28 inches. The Black Crappie gill and trap net catch rates were above and below average. The gill net catch in 2025 was 17.1/net, which compares to the average of 11.0/net. The trap net catch was 1.8/net, which compares to the average of 3.5/net. Black Crappie are more consistently sampled in gill nets than trap nets. Crappie caught in gill nets ranged in length from 6.3 to 11.3 inches and had an average length of 9.0 inches. Crappie over 10 inches have been sampled in the past six consecutive surveys with both gill and trap nets, while crappie over 12 inches have been sampled in two of those surveys. The population currently has a high proportion of fish over eight inches and ten inches. Overall, anglers that fish Green Lake for crappies can expect to catch good numbers of 8 to 11-inch fish. Night electrofishing surveys to evaluate Largemouth Bass relative abundance and size structure were conducted in June 2025 for the seventh consecutive survey. The 2025 catch rate was 162/hour which was the highest observed. Catch rates varied from 12/hour in 2002 to 162/hour in 2025 and have averaged 57/hour. Lengths of bass sampled ranged from 3.6 to 19.5 inches and averaged 11.9 inches. The average length for the 2021 survey was similar, at 12.1 inches. Bass over 15 inches were sampled in all seven surveys, while bass over 20 inches have never been sampled. Green Lake has average proportions of bass over 12 and 15 inches. Anglers can expect to catch high numbers of bass between 12 and 16 inches, with a chance at a bass over 18 inches. The 2025 Bluegill trap net catch rate of 45.9/net was way above the average of 10/net. Bluegill ranged from 2.4 to 9.0 inches with a 4.6-inch average. Although Bluegills over 8 inches were sampled in 11 of the 16 surveys, including every survey since 2002, their numbers are consistently low. The population has below average proportions of fish over 6 inches and 8 inches. Yellow Perch gill net catch rates are typically high when compared to other Isanti County area lakes. Catch rates in 2025 were 81/net and compare to the average of 121/net. Gill net catch rates have varied from 3/net in 2021 to 641/net in 1957. The perch sampled in 2025 ranged from 5.4 to 8.1 inches and had an average length of 6.5 inches. Eight-inch perch have been sampled in 5 of the last 8 surveys, while 10-inch perch have been sampled in one. The average size is likely too small to interest anglers; however, they are an important prey source for most gamefish targeted by anglers. Additional gamefish species sampled include Black Bullhead, Brown Bullhead, Green Sunfish, Hybrid Sunfish, Pumpkinseed, Rock Bass, Smallmouth Bass, and Yellow Bullhead.

Crappie were collected as part of a broad research project investigating populations across Minnesota. Springtime trap net surveys collected a total of 241 fish. Individuals averaged 9.1 inches with the largest individual being 11.4 inches. Growth was moderate and individuals averaged 7.6 and 9.8 inches at age 3 and 6, respectively. Maximum age was 12. A research survey collected Black Crappie as part of a broad statewide research project investigating population demographics and dynamics across Minnesota. Fish were collected using springtime trap nets targeting pre-spawn feeding patterns. A total of 241 fish was collected in the spring of 2025. Average and maximum total length was 203 and 287 mm, respectively. Age distribution extended from 2 to 12 with variable year class formation (3 missing cohorts). A von Bertalanffy growth curve was fit (Linfinity = 262 mm, K = 0.57, t0 = 0.71) and indicated moderate growth rates. Average total length of age-3 and age-6 individuals was 191.3 and 249.6 mm, respectively. Recruitment was irregular (RVI = 0.21, RCD = 0.11). Total annual mortality was estimated using a weighted catch curve (A = 0.24; 95 CI = 0.19 to 0.29). An estimate of total annual mortality exceeds the approximates the first quartile of mortality rates (A = 0.23) in similar Minnesota lakes

Green Lake is an 802 acre basin managed for Walleye and Northern Pike. There is one public access located on the north side of the lake. Water clarity is moderate with algal blooms present as summer progresses. The Walleye population is currently maintained through biennial fingerling stocking (even numbered years). Green is in lake class 27. In 2021 a fisheries survey was conducted which included trap netting and gill netting from August 20th through August 23rd. Nine gill net sets and nine trap nets were used during the assessment. The previous assessment on Green Lake was conducted in 2016. The Northern Pike catch rate was 4.9 fish per net which is within the interquartile range for the lake class and similar to the historic catch for the lake. Mean weight of pike sampled was 3.5 lbs. Gill net catches for Walleyes were 3.7 fish per net. This is lower than the 2016 survey of 4.1 fish per net but still within the range typical for the lake class. Mean weight was above the lake class median at 2.3 lbs. Black Crappie catch in gill nets was high with 6.8 per net, well above average for this lake class. Sixty-seven percent of the crappie catch exceeded 8 inches in length. Mean weight of crappies was 0.31 lbs. The Bluegill catch rate was 18.0 fish per net. This was similar to historical catches and average for the median catch for the lake class. Mean weight was also typical for the lake class and historical surveys. Bluegill sampled ranged from 1.0 to 9.1 inches and averaged 5.1 inches in length. Just 8 percent of the Bluegill sampled exceeded 7 inches in length. Spring electrofishing found a Largemouth Bass catch rate of 56 fish per hour, similar to 54 per hour caught in 2016. Bass averaged 12.1 inches and 1.2 lbs., ranging in length from 6.3 inches to 19.5 inches.

Based on Minnesota DNR survey data, anglers target Largemouth Bass, Black Crappie, Northern Pike, Walleye, and Yellow Perch in Green. See the full species list above for catch rates, size structure, and quality scores.

Minnesota DNR records list public access for Green. Check the DNR LakeFinder page for the launch type and directions before you go.

Green has a maximum depth of 28 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Green is from 2025.

Yes — Green has confirmed Eurasian watermilfoil. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.