Knife

Knife Lake is a 1,266-acre lake in central Kanabec County located six miles north of Mora and is within the Snake River Watershed. The lake has a maximum depth of 16 ft and 99% of the lake is 15 feet or less (1,259 littoral acres). Knife River flows originate from groundwater, which allows cool water species such as walleye to flourish. Eggs were collected and fertilized from Knife River Walleyes April 10-18, 2025. This was the third consecutive year Walleyes were spawned since efforts resumed in April 2023. Prior spawning operations occurred from 1977-85. The fry produced are classified as LMS (Lower Mississippi River Strain). Due to this spawning operation, 315,000 fry (250 per littoral acre) are stocked back into Knife Lake annually, and 400,000 fry are stocked back in the Knife River annually. Due to higher than anticipated survival rates in the St. Paul hatchery in 2025, an additional 400,000 surplus fry were stocked back into the Knife River. The Knife River is 16 miles long and is stocked at five locations. Stocking occurred from May 2-4, 2025. Knife Lake was electrofished on the night of October 20, 2025, to evaluate the relative abundance of stocked and naturally produced juvenile Walleye. The water temperature was 55°F. Nine 10-minute stations were sampled. These stations were established in the fall of 2025 to conform with standardized statewide protocols. Past electrofishing evaluations have confirmed juvenile Walleye are the result of both natural reproduction and stocking. The 2025 age-0 walleye catch rate of 109/hour was higher than the lake average of 76/hr. The average catch rate of LMS stocked years is 252/hour, while the average of non-LMS stocked years is 52/hour. Age-0 Walleye ranged from 5.6 to 8.0 inches in length with a 7.0-inch average. The catch rate of Age-1 and Age-2 Walleye was 52/hour. Age-2 Walleye made up the majority of this catch. Age-1 Walleye ranged in length from approximately 9.5 to 11.5 inches, while age-2 walleyes ranged in length from approximately 11.5 to 13.5 inches. Additionally, numerous larger Walleye were observed and not netted. The high likelihood of natural Walleye reproduction makes the fry stockings contribution to the Walleye year classes unknown.

A targeted survey of nearshore fish species in Knife Lake, was conducted on August 25 - August 26,2025, by Lake Biological Monitoring and Assessment program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Backpack electrofishing was completed at eighteen sampling stations. Similarly, a 50-foot seine was used to sample ten stations, and a 15-foot seine was used at four stations. Four stations were not seined due to dense vegetation. Nearshore sampling captured seventeen species of fish, including four species that are intolerant of disturbance (i.e., Logperch, Mimic Shiner, Rock Bass and Smallmouth Bass) and no species that are tolerant of disturbance. The nearshore data were combined with trap net and gill net data from a June 2025 survey to describe the fish community and provide a fish-based index of biological integrity (FIBI) score. The FIBI uses fish community data to measure a lake's health, and the types of fish species present can help identify any stressors that may be negatively affecting the lake environment. In Minnesota lakes, certain fish species cannot survive without clean water and a healthy habitat (e.g., Blackchin Shiner, Iowa Darter, and Rock Bass), while other species are tolerant of degraded conditions (e.g., Green Sunfish and Common Carp). The FIBI score, composed of several fish community diversity and composition metrics, indicates the overall health of a lake by comparing it to what is expected for a healthy lake. For additional information on the FIBI, search for "lake index of biological integrity" on the mndnr.gov website. Results from this survey provide evidence that the fish community in Knife Lake is healthy as indicated by an FIBI score above the general use impairment threshold for aquatic life use determined for similar lakes. These results are similar to previous findings which indicated that Knife Lake is fully supporting aquatic life. The survey results will be considered when the biological health of the lake is assessed during the Snake River watershed assessment process, which will be completed in coordination with MN Pollution Control Agency. You can help protect the fish community in Knife Lake by reducing runoff, maintaining natural shorelines, and preventing the spread of invasive species.

Knife Lake is a 1,266-acre lake located six miles to the north of Mora in Kanabec County and is within the Snake River Watershed. The lake has a maximum depth of 15 feet and an average depth of 9 feet. It is 100% littoral (15 feet or less). Water clarity is generally low due to frequent algae blooms, with Secchi depths near 2 feet. The Knife River enters Knife Lake on the southwest side and exits the lake to the south, flowing into the Snake River 5 miles downstream. Submergent and floating leaf vegetation is generally dense in depths up to 7 feet. Invasive species present include Curlyleaf Pondweed, Eurasian Watermilfoil, and Faucet Snails. Substrates consist primarily of sand, with some gravel and muck. There are two public boat accesses, one on the south side and one on the east side off of Highway 65. The south access accommodates 8 vehicles with trailers and is a gravel parking lot. The access on Highway 65 is paved and accommodates 15 trucks and trailers. Including the initial survey in 1949, twenty-five fish surveys have been completed to monitor changes in species composition, number, and length distribution. More recent surveys have occurred in 2015, 2019, 2022, and 2025. Gamefish species that are best suited for the lake include Walleye, Northern Pike, Black Crappie, Bluegill, Largemouth Bass, and Yellow Perch. Walleye have a Special Regulation on Knife Lake, with an 18-to-24-inch protected slot, statewide possession of 6, only 1 of which can be over 24-inches. A total of 139 Walleyes were sampled in gill nets in 2025, which resulted in a catch rate of 11.6/net. This is similar to the average of 12.2/net, but the highest catch rates observed since 1998. Past catch rates ranged from 0.5/net in 1985 to 47.0/net in 1991. Lengths of Walleye caught in 2025 ranged from 6.5 to 26.6 inches and averaged 13.5 inches. Twenty inch Walleye have been sampled in the last 9 consecutive surveys, while 25-inch Walleye have been sampled in 5 of the past 9 surveys. Overall, anglers that fish Knife Lake for Walleye can expect to catch good numbers of 12 to 15-inch fish with a chance of catching one over 20 inches. Northern Pike have a Special Regulation on Knife Lake, with a 24-to-36-inch protected slot, possession of 3, only 1 of which can be over 36-inches. A total of 39 Northern Pike were sampled in gill nets in 2025, which resulted in a catch rate of 3.3/net. This is similar to the average of 3.5/net. Past catch rates ranged from 0.0/net in 1990 and 1991 to 11.3/net in 1981. 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. Therefore, pike densities in Knife Lake are optimal. Lengths of pike caught in 2025 ranged from 17.0 to 35.3 inches and averaged 24.8 inches. The largest pike sampled was a 41.5 inch fish in 2011. Twenty-eight inch pike have been sampled in the last 8 consecutive surveys, while pike over 34 inches have been sampled in 5 of the past 8 surveys. Overall, anglers that fish Knife Lake for pike can expect to catch lower numbers of medium to large sized pike, with a chance of catching one over 34 inches. A total of 46 Black Crappie were sampled in gill nets in 2025 while 122 were sampled in trap nets. The gill net catch was 3.8/net in 2025 and compares to the average of 15.4/net. The trap net catch was 11.1/net in 2025 and compares to the average of 8.0/net. Gill nets have consistently sampled crappies at a higher rate than trap nets in Knife Lake. Crappie ranged in length from 4.3 to 13.4 inches and had an average length of 9.0 inches for both gears. Crappie over ten inches have been sampled in all nine of the most recent surveys, while crappies over 12 inches have been sampled in five of nine surveys. Overall, anglers that fish Knife Lake for crappies can expect to catch average numbers of 8 to 10 inch crappies, with a chance of catching one over 12 inches. A total of 107 Bluegill were sampled in trap nets in 2025, which resulted in a catch rate of 9.7/net. This is similar to the average of 10.5/net. Catch rates have varied from 1.0/net in 1949 to 32.2/net in 1994. Lengths ranged from 3.3 to 9.8 inches and averaged 6.6 inches. Bluegills over 8 inches have been sampled in 7 of the previous 9 surveys in trap nets. Bluegill over 10 inches were sampled in gill nets in 1979, 2011, and 2019. In 2011, a 12.2-inch Bluegill was sampled. Anglers targeting Bluegill on Knife Lake can expect to catch average numbers of 6 to 8 inch fish. Nighttime electrofishing surveys to evaluate Largemouth Bass relative abundance and size structure were conducted in June of 2025 for the eleventh survey. A total of 202 were caught in 2025 for a catch rate of 135/hour. This was the second highest recorded catch rate for Knife Lake and exceeded the lake average of 74/hour. Catch rates have varied from 18/hour in 2022 to 136/hour in 1993. In 2025, bass ranged from 3.6 to 16.9 inches and had a 10.0 inch average. Bass over 20 inches have never been sampled. Currently, anglers can expect to catch high numbers of bass from 8 to 16 inches. Yellow Perch catch rates continue to remain high compared to area lakes. A total of 250 perch were sampled in gill nets in 2025. Perch gill net catch rates were 20.8/net in 2025, which compares with the average of 25.4/net. Catch rates have varied from 0.0/net in 1990 to 56.0/ net in 1970. Lengths ranged from 5.5 to 10.3 inches and averaged 7.8 inches. Perch over 8 inches have been sampled in 8 of the last 9 surveys, while perch over 10 inches have been sampled in 5 of the past 10 surveys. At times, harvestable sized perch are available for anglers. The current perch population and its average size is likely too low and small to interest anglers; however, they can be an important prey source for most gamefish targeted by anglers. Additional species sampled include Black Bullhead, Brown Bullhead, Central Mudminnow, Green Sunfish, Golden Redhorse, Golden Shiner, Greater Redhorse, Hybrid Sunfish, Iowa Darter, Johnny Darter, Logperch, Northern Hogsucker, Northern Redbelly Dace, Pumpkinseed, Rock Bass, Shorthead Redhorse, Tadpole Madtom, Yellow Bullhead, and White Sucker.

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

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

Knife has a maximum depth of 15 feet and a mean depth of 9.1 feet, per Minnesota DNR data.

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

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