South Farm

Temperature and dissolved oxygen measurements were collected from the deepest basin in South Farm Lake on July 31st, 2025. This was done to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake. Cisco require a layer of oxythermal habitat that contains water temperatures below 21.2 degrees C (70.2 degrees F) and dissolved oxygen concentrations above 3.0 mg/L. Based on data collected from the deepest basin (maximum sampled depth was 26.2 feet), the water temperature decreased to 21.2 degrees C (70.2 degrees F) at 10.6 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 13.2 feet at the time of sampling. This layer in the water column was 2.7 feet, indicating oxythermal habitat for Cisco was present but marginal. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 19.4 degrees C (66.9 degrees F). TDO3 values cooler than 21.2 degrees C (70.2 degrees F) indicate that oxythermal conditions were marginal for Cisco at the time of the survey as the layer was confined to less than 3 feet of suitable habitat at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the period of maximum oxythermal stress (July 26th to Aug 24th) in 4 years, between 2008-2024, also indicated suitable oxythermal habitat in all years surveyed, with the least favorable conditions recorded in 2024 when the suitable oxythermal habitat layer was 0.5 feet thick. When adequate oxythermal habitat is not available, Cisco are squeezed into unfavorable, warmer water conditions and experience higher levels of stress. On South Farm Lake, when adequate oxythermal habitat is not available, fish can move out of the lake into Farm Lake which contains better oxythermal conditions for Cisco.

South Farm Lake is five miles southeast of Winton, covers 564 acres, and is one of three connected lakes that with Farm and Garden comprise the Garden Reservoir. This system is also connected to White Iron Lake via the South Kawishiwi River. The primary access is via navigable channel from Farm Lake. A hydroelectric dam at the outlet of Garden Lake affects water levels seasonally on South Farm Lake and the other connected lakes. South Farm Lake is located entirely within the BWCAW where visitor use permits are required and motor use on the lake is limited to 25-hp or less. The 2020 lake management plan for the Garden Reservoir lakes listed walleye and northern pike as the primary management species and the plan also listed bluegill, smallmouth bass, and black crappie as capable of providing quality fishing. A standard survey was conducted in mid-summer 2023 to assess the populations of these species and to monitor lake quality and habitat. The survey crew sampled fish with gill nets and trap nets, and they measured water quality. Garden Lake was thermally stratified, with a surface temperature of 67 F and a temperature of 46 F at 27 feet. Adequate oxygen levels for gamefish were present to a depth of about 15 feet. South Farm has brown, bog-stained water with visibility around 6 feet. Shoreline substrates are predominantly rocky, although some of the bays have muck bottoms and fair amounts of aquatic vegetation. Walleye harvest by anglers on the Garden Reservoir chain is restricted with a special regulation that requires releasing all fish from 17 to 26 inches, with only one fish over 26 inches allowed in a 6-fish limit. This regulation has been in place since 2006 with the goal of maintaining overall catch rates while increasing the number of fish over 17 inches and applies to all the connected lakes mentioned above. In South Farm, the gill-net catch for walleye was higher than the historic median for the lake. Walleye were 14.2 inches long on average and 40% of the fish were over 14.0 inches. Fourteen additional walleye were also caught in trap nets with a similar average size of 13.4 inches. Walleye ages ranged from 2 to 12 and indicated natural reproduction is occurring in the system. Northern pike (pike) harvest by anglers on the Garden Reservoir chain is restricted with a special regulation that requires releasing all fish from 24 to 36 inches, with only one pike over 36 inches allowed in a 3-fish limit. This regulation, which applies to all the connected lakes mentioned above, has been in place since 2003 with the goal of maintaining the overall catch rate and increasing the abundance of pike over 24 inches. In South Farm, pike were sampled at a rate of 3.8 fish/gill net, which was the highest catch per survey net ever recorded on South Farm Lake. The pike averaged 24.5 inches in length, which was smaller than the historical average for the lake. Additional pike were sampled in trap nets at a rate of 2.9 fish/trap net. These fish tended to be smaller, averaging 21.0 inches. Bluegill were caught at rates that were below the historic median for the lake. Bluegill averaged 6.9 inches in length and displayed some of the fastest growth compared to other bluegill populations in the Tower area. The largest bluegill was 9.4 inches in length, and ages ranged from 2 to 12. Black crappie were caught at rates that were above the historic median for the lake. Black crappie averaged 10.3 inches in length. The largest black crappie was 14.1 inches long, and ages ranged from 2 to 8. Additional species sampled in 2023 included burbot, cisco, golden shiner, rock bass, white sucker, and yellow perch.

South Farm Lake is located approximately 5 miles SE of Winton and is entirely within the BWCAW where a 25 hp motor limit is in effect. Visitors should be familiar with USFS regulations when accessing South Farm. South Farm is one of four connected lakes that with Farm, White Iron and Garden comprise the Garden Reservoir. Seasonal water level fluctuations are common. The most common access is by a navigable channel from Farm Lake. There is also a small gravel ramp located near the end of the Kawishiwi Trail (CR 16) where a small boat or canoe could easily be launched. There are two designated USFS campsites located on South Farm. Eight species of fish were sampled with 6 gill nets in 2017. Cisco made up 65% of the catch, followed by walleye ( 12%), and northern pike (8%). South Farm has a healthy population of black crappie although only 2 were sampled in the gill nets. Three smallmouth bass were also sampled. Walleye numbers in 2017 (3.8/gill net) were slightly higher than the long term average (2.4/gill net) for this lake. The average walleye sampled was 16.1 inches and about 6 to 7 years old. The largest walleye sampled was 26 inches. Walleye fingerlings are stocked during odd numbered years and 79% of the walleye sampled in 2017 came from years where fingerlings were stocked. There has been a protected slot for walleye between 17 and 26 inches with one over 26 inches in possession since 2006. Northern pike numbers in 2017 (2.7/gill net) were slightly higher than the long term average (1.3/gill net) for South Farm Lake. The average pike sampled was 23.9 inches and the largest pike was 32.4 inches long. There has been a protected slot for northern pike between 24 and 36 inches with one over 36 inches in possession since 2003. Since the slot regulation was implemented, more large pike (24 inches or more) have been sampled in Garden Lake Reservoir.

Based on Minnesota DNR survey data, anglers target Black Crappie, Northern Pike, Bluegill, Walleye, and Rock Bass in South Farm. See the full species list above for catch rates, size structure, and quality scores.

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

South Farm has a maximum depth of 31 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in South Farm is from 2023.

No invasive species are on record for South Farm in Minnesota DNR data. Always clean, drain, and dry your equipment to help keep it that way.