Big Stone

Lake sturgeon were historically present in Big Stone Lake but had been extirpated by around 1950 likely due to winterkill, summerkill, overharvest and barriers to spawning migrations. Lake sturgeon were reintroduced in 2014 and approximately 4,000 fingerlings had been stocked annually (excluding 2020), totaling 44,500 as of 2024. Stocking will occur every third year thereafter, with the next scheduled in 2027. This targeted survey was conducted to document the size distribution and relative abundance of lake sturgeon in Big Stone Lake. Large-mesh gill nets were used to specifically target large fish. Over a three day period during October 2025, 137 lake sturgeon were caught. Their lengths ranged from 36 to 58 inches. Thirty-four percent were 50 inches or larger. The largest sturgeon measured 58 inches and 64 pounds and was 11 years old. Stocking has been successful as sturgeon are abundant, growing fast, are in good physical condition and are frequently caught by anglers and in DNR surveys. This was a specific assessment targeting lake sturgeon so these data are not comparable to data from standard gill nets used to sample all species that are reported in other Big Stone Lake reports.

Big Stone Lake is in western Minnesota adjacent to the town of Ortonville on the Minnesota-South Dakota border. It is 27 miles long, up to one mile wide, 12,610 acres, and has a maximum depth of 16 feet. The Minnesota Department of Natural Resources and South Dakota Department of Game, Fish and Parks co-manage the fishery and Border Waters fishing regulations apply. Big Stone provides good fishing for bluegills, largemouth bass, walleyes, yellow perch, white bass, black crappies and freshwater drum. This Targeted Survey was conducted to collect routine fish population data using gill nets and shoreline seining. This data can be compared to historical Standard and Targeted Survey data from Big Stone Lake. Yellow perch numbers in 2025 were lower than the historic highs observed in previous years, but the number of perch over 10 inches was higher than in recent surveys. Perch fishing can still be good, though it may take more time to find the larger schools. Largemouth bass, bluegill and black crappie numbers have increased significantly during recent years. This is largely due to a substantial change in habitat, with rooted plants becoming much more abundant and the water becoming clearer. This habitat type suits these species very well. The largemouth bass population has been so impressive that Big Stone has become a "destination lake" for bass anglers and tournaments. Bluegills have grown fast and anglers frequently catch them larger than 9 inches. Anglers have also been catching quality-sized black crappies. Walleyes were present in good numbers and from a wide range of sizes. Walleyes from the 2023 year class were abundant and measured 12-18 inches. Relatively high numbers of walleyes over 25 inches were also present. Walleyes in Big Stone Lake grow fast and some can reach 14 inches after two summers. Natural reproduction and supplemental fry stocking have maintained the population. Walleyes often have plenty of forage available which can make them difficult to catch at times. Northern pike numbers have generally been low, however, enough trophy-sized pike have been present to attract attention. Some anglers and spearers have reported decent success fishing for pike. Fishing for white bass and freshwater drum has been good in recent years. These species have white flesh and are good to eat. Their flavor can be improved by keeping slime off the fillets when cleaning them and by trimming away the reddish meat from the skin side of the fillets. Lake sturgeon have been stocked since 2014 and they have survived well. It has become common for anglers to see and catch them, with some near 60 inches being caught. Anglers can catch and release sturgeon during the open season, but no harvest is permitted. Consult the Minnesota and South Dakota fishing regulations for more information including season dates. Curly-leaf pondweed has become well established in Big Stone Lake since first being found in the early 2000's. It can grow to the water's surface over much of the lake during early summer but usually dies back in July. The amount of curly-leaf that grows each year can vary considerably based on water clarity. Although the plant can provide challenges for boating and fishing, it provides valuable fish habitat for many desirable species.

A targeted survey of nearshore fish species in Big Stone Lake, was conducted on July 28- 31, 2025, by Lake Biological Monitoring and Assessment (LBMA) 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 24 sampling stations. Similarly, a 50-foot seine was used to sample 14 stations, and a 15-foot seine was used at nine stations. One station was not seined due to deep water and large boulders throughout the sampling area. Nearshore sampling captured 21 species of fish including two species that are intolerant of disturbance (i.e., Iowa Darter and Rock Bass) and five that are tolerant of disturbance (i.e., Black Bullhead, Common Carp, Fathead Minnow, Green Sunfish, and Orangespotted Sunfish). A concurrent summer trap net survey was also conducted by LBMA staff 20 trap nets were set along the shoreline in locations that encompassed multiple habitat types. Trap net sampling captured 13 species of fish. Freshwater Drum and Common Carp comprised a majority of the catch by number and biomass. The nearshore and trap net data were combined with gill net data from a September 2025 survey to describe the fish community and provide a fish-based IBI (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 web site. Results from this survey provide evidence that the fish community in Big Stone Lake may be adversely impacted by stressors and is near the impairment threshold for aquatic life use determined for similar lakes. These results are similar to previous findings which also indicated that Big Stone Lake was vulnerable to impairment. The survey results will be considered when the biological health of the lake is assessed during the Minnesota River Headwaters watershed assessment process, which will be completed in coordination with MN Pollution Control Agency. You can help protect the fish community in Big Stone Lake by reducing runoff, maintaining natural shorelines, and preventing the spread of invasive species.

Based on Minnesota DNR survey data, anglers target Yellow Perch, Hybrid Sunfish, Northern Pike, Walleye, and Bluegill in Big Stone. See the full species list above for catch rates, size structure, and quality scores.

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

Big Stone has a maximum depth of 16 feet and a mean depth of 11 feet, per Minnesota DNR data.

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

Yes — Big Stone has confirmed zebra mussel. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.