Split Rock Reservoir

Split Rock Lake is an impoundment created by a dam on Split Rock Creek constructed in 1938. This reservoir is located entirely within the boundaries of Split Rock State Park near Ihlen in Pipestone County. It has a surface area of 80 acres, a maximum depth of 16 feet, Secchi depth of 2.5 feet, and is a class 42 lake. Pipestone County does not have a "natural" lake, however Split Rock Lake is one of four reservoirs that fisheries has interest in. To increase angling opportunities in the area, a shoreline fishing pier is maintained on the northwest corner of the reservoir. The lake is managed primarily for Yellow Perch, Bluegill, and Black Crappie with no secondary management species. Due to the presence of Topeka Shiner, an endangered species, within Split Rock Creek, a memorandum of understanding is in place between the United States Fish and Wildlife Service and Minnesota Department of Natural Resources to only stock Bluegill within Topeka Shiner Watersheds. To evaluate fish populations and management goals an assessment utilizing one gill net and six trap nets was conducted during the week of July 7, 2025. The Black Crappie catch rate in 2025 was 19.3 per trap net which is high compared to similar lakes. The 2025 catch rate increased from the 2013 rate of 15.7 per trap net and is approaching the long-term average of 21.3 per trap net. Lengths of Black Crappie sampled in trap nets ranged from 4.2 inches to 11.9 inches with a mean length of 6.5 inches. Growth of these fish was very good based on an overall relative weight (Wr) of 106. Although no aging of Black Crappie was done, length frequency groupings appear to indicate at least three-year classes. Bluegill catch rates have been highly variable, ranging from 0.4 per trap net in 1987 to 19.0 per trap net in 1997. The Bluegill catch rate in 2025 was 1.8 per trap net, which is just below the expected range of catch rates for similar lakes (1.9 to 29.5 per trap net). Declining bluegill populations appear to be directly related to elevated common carp catches since 1997, along with the lack of submergent vegetation associated with poor water clarity. Bluegill typically thrives in clear water systems with abundant vegetation, conditions that are likely lacking in Split Rock Reservoir since Common Carp abundance increased. Lengths for bluegill from trap nets ranged from 3.9 to 6.5 inches with a mean length of 5.1 inches. Yellow Perch abundance continued to be low, as the catch rate has been 3.0 per gill net or less since 1997 and was 1.0 per gill net in the 2025 survey. Like Bluegill, Yellow Perch abundance appears to be strongly correlated to the arrival and continued presence of Common Carp in the lake. Yellow Perch lengths ranged from 6.1 to 8.7 inches and averaged 7.4 inches. Adult Yellow Perch are present and should have the capability to reproduce and sustain the population when conditions are favorable. The White Sucker catch rate was 142.0 per gill net, much greater than the long-term average of 23.1 and greatly exceeding the expected range of catch rates for similar lakes. Lengths of White Suckers from both gears ranged from 4.6 to 17.8 inches and averaged 11.6 inches. Prior to 2001, White Suckers were not present in Split Rock Lake. Other fish species sampled during this assessment in low densities included Black Bullhead, Common Carp, Northern Pike, Orange Spotted Sunfish, Green Sunfish, Hybrid Sunfish, Pumpkinseed, Tadpole Madtom, and Channel Catfish.

Split Rock Lake is an impoundment created by a dam on Split Rock Creek constructed in 1938. This reservoir is located entirely within the boundaries of Split Rock State Park near Ihlen in Pipestone County. It has a surface area of 80 acres, a maximum depth of 16 feet, transparency depth of 2.0 feet, and is in lake class 42. Minnesota DNR Fisheries classifies lakes with similar characteristics, such as size, depth, water chemistry, and other metrics on a statewide basis for comparison of fish communities. A winter aeration system is operated on the lake but occasional partial winterkills still occur. This lake is only one of four small reservoirs in Pipestone County which has no "natural" lakes. To increase angling opportunities in the area, a shoreline fishing pier is maintained on the northwest corner of the reservoir. The lake is managed primarily for yellow perch, bluegill sunfish, and black crappie with no secondary management species. Due to the presence of the endangered Topeka Shiner within Split Rock Creek, the division of fisheries is not allowed to stock predators such as walleye, northern pike, largemouth bass, or channel catfish in the reservoir. To evaluate fish populations and management goals, an assessment utilizing one gill net and nine trap nets was conducted during the week of July 8, 2013 with the following results. Black crappie catch rate in trap nets, of 5.7 per net, is slightly under the long-term average for this lake. Although this is a decline from the record high catch of 42 per net in 2007, good numbers of crappie remain. Lengths of fish sampled in trap nets ranged from 4.4 to 12.4 inches with a mean length of 8 inches. The fish are healthy and foraging successfully resulting in good growth rates. No aging of crappies was done, but length frequency groupings appear to indicate at least five year classes present. They are reproducing successfully, and should continue to provide an angling opportunity for years to come. Bluegill sunfish catch rates have shown a steady decline from a peak of 19 per trap net in 1997, to 8.6 in 2001, 4.4 in 2007, and 0.6 during 2013. Declining bluegill populations appear to be directly related to elevated common carp catches since 1997, along with the lack of submergent vegetation associated with poor water clarity. Lengths for bluegill from trap nets ranged from 4.9 to 8.6 inches with a mean length of 6.6 inches. These fish are foraging successfully indicated by healthy fish in the sample. Length frequency distribution groupings appear to indicate four year classes of bluegill present during this survey. Since bluegill numbers are low and sizes are somewhat small, more adult bluegills will be stocked to boost the population in 2014. Gill net catch rates for yellow perch have dropped from 3 per net in 2007 to zero per net during 2013. Although no perch were sampled in gill nets, a total of seven fish were captured in the trap nets for a catch rate of 0.8 per net. This is equal to the long term average for trap nets from seven surveys on this lake dating back to 1987. Perch lengths in trap nets ranged from 5.3 to 8.5 inches with a mean length of 6.4 inches. There appear to be two year classes of perch present based on length frequency groups. Long-range plan goals are not being met for perch numbers, therefore yellow perch adults will be stocked to enhance the population in 2014. White Sucker catch rates of 38.0 per gill net are six times the long-term average for this lake. Trap net catches of 2.6 per net were also more than double the long-term average. Since no white suckers were sampled prior to 2001, catches from both gear types are at all time high levels and rising rapidly. Lengths from both gears ranged from 7.5 to 15.4 inches with an overall mean length of 13.7 inches. Black Bullhead catch rates of 46.0 per gill net and 6.0 per trap net were both very near the long-term average catch rates for this reservoir. Lengths of bullheads from both gear types ranged from 4.6 to 8.8 inches with an overall mean length of 6.7 inches. Common Carp catch rates of 23.0 per gill net and 2.7 per trap net were both nearly double the long-term average catch rates for Split Rock reservoir. Lengths of carp from both gear types ranged from 13.0 to 22.0 inches with an average weight of 2.0 pounds. Other fish species sampled during this assessment in low densities included Northern Pike, Orange Spotted Sunfish, Green Sunfish, and Channel Catfish. Split Rock reservoir also provides excellent turtle habitat with 24 painted turtles and 18 snapping turtles captured in the nine trap net sets.

Split Rock Reservoir, located in Split Rock State Park, is an 81-acre impoundment in Pipestone County. Split Rock Reservoir has a watershed ratio of 128:1, which makes it highly vulnerable to landscape uses and precipitation events. Its maximum depth is 16 feet, but most of the reservoir averages around 6 feet deep. Water quality issues have made fish management a challenge. Significant effort has been made during its history to improve the water quality and fishery with the reservoir with limited success. In November of 1986, Split Rock Reservoir and other upstream bodies of water within the watershed were reclaimed. Although the reclamation was not completely successful in eradicating all bullheads, a respectable largemouth bass, crappie, bluegill, yellow perch, and walleye fishery became established a few years later. In 1993, a portion of the Split Rock Reservoirs earthen dam was breached, which essentially returned it to a free flowing creek. Soon after the repair in fall of 1993/winter of 1994, adult largemouth bass, walleye and bluegill were restocked to create a fishery. Assessments following those restocking efforts saw a more diverse fishery, with panfish dominating the fish community. Unfortunately, the failure of the dam in 1993 enabled common carp to become reestablished in the Split Rock Reservoir and upstream. The Split Rock Creek watershed has Topeka shiners, a federally listed endangered species. The DNR and US Fish and Wildlife Service issued a directive ceasing any future predator stockings (channel catfish, largemouth bass, walleye, and northern pike) within the watershed because of the potential threat of predation on Topeka Shiners. A resurvey was conducted during the week of July 9, 2007 using a gill net, 5 trap nets, and 2 seine hauls. Walleye abundance in the reservoir is very limited. The last walleye fingerling stockings occurred in 2000 and 2001. As a result, only 1 19-inch walleye was sampled during the survey. Anglers should consider themselves quite fortunate if they were to catch a few of the remaining walleye. Northern pike numbers have been historically much higher. The catch rate was within the normal range and proves there is natural reproduction, as they have not been stocked since 1983. Total lengths ranged from 18.7 to 22.2 inches with an average of 20.5 inches. It is possible northern pike numbers could sporadically increase in the future as northern pike abundance is often influenced by seasonal weather patterns and habitat availability. With a little luck, an angler may get one of these generally aggressive fish to latch on to their lure. The black crappie catch rate was the highest ever seen in Split Rock Reservoir, at nearly 3 times the expected range. Total lengths ranged from 4.0 to 9.4 inches with an average of 6.4 inches. A majority (56%) of the fish were 6.5-8.5 inches. The condition of the crappies indicates they were finding plenty of forage and were healthy. Great shore fishing areas within the park may be a great way to spend some time fishing with the kids. The bluegill catch rate in trap nets was 4.4/set, which was within the expected range. Total lengths ranged from 4.2 to 7.3 inches with a mean of 6.4 inches. Bluegill natural reproduction appears to have been successful in 2007 as seine hauls captured 147 young of the year Age 0 bluegill. If submergent vegetation improves within the reservoir, it would likely improve the bluegill fishery. No largemouth bass were sampled in gill nets or trap nets. However, 4 Age 0 largemouth bass were sampled in a seine haul, which indicated the presence of mature largemouth within the reservoir and indicates some natural reproduction occurred in 2007. Only 2 channel catfish were sampled in gill nets and trap nets combined. Natural reproduction occurred in 2007 as 1 3-inch channel catfish was sampled in a seine haul in 2007. The catch rate of black bullhead in gill nets was 32/set, which was within the expected range. Total lengths of bullheads in gill nets ranged from 4.9 to 8.7 inches with a mean of 7.8 inches. Although numbers have been higher, Split Rock Reservoir would still be a good destination for some good fishing action for the kids. The catch rate of common carp in gill nets was 13.0/set, which was 3 times the expected range. All of the fish were 17-20 inches. Unfortunately these fish can impact a small fishery by rooting up aquatic vegetation and making the water more turbid. Other species sampled were green sunfish, white sucker, fathead minnow, orangespotted sunfish, and shiners. Efforts to improve the health of the lake should focus on best management practices within the watershed. Improvements and education in land stewardship will often have secondary benefits to the lake in the way of quality and quantity of habitat. Generally, improvements in the quality and quantity of lake habitat will mean direct improvements of the fishery. Prepared by Ryan Doorenbos

Based on Minnesota DNR survey data, anglers target Channel Catfish, Black Crappie, Hybrid Sunfish, Walleye, and Green Sunfish in Split Rock Reservoir. See the full species list above for catch rates, size structure, and quality scores.

We don't have a confirmed public access point on record for Split Rock Reservoir. Check the DNR LakeFinder page for current access details before you go.

Split Rock Reservoir has a maximum depth of 16 feet, per Minnesota DNR data.

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

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