Rock

Rock Lake is a 439-acre, class 43 lake, located approximately 3 miles south of the City of Russell in Lyon County. Rock Lake is managed primarily for Walleye and secondarily for Yellow Perch. Lower Mississippi Strain Walleye were stocked in Rock Lake in 2016, 2018, 2021, 2022, and 2024. Walleye were not stocked in 2020 because of the COVID-19 pandemic, so Walleye were stocked in 2021 despite being an "off" year. A Walleye fry stocking evaluation using daytime electrofishing was conducted on September 11, 2025 to determine if natural reproduction of Walleye occurred during a non-stocked year in Rock Lake. Young-of-the-year (YOY) Walleye were captured at a rate of 132.0 per hour, which indicates that natural reproduction occurred in Rock Lake. Walleye fingerlings were 5.2 to 7. inches in length and averaged 5.4 inches. Assuming survival to Spring of 2026, the 2021 year class should be a strong year class in the Rock Lake Walleye population.

Rock Lake is a 439-acre lake located south of the City of Russell in Lyon County. Rock Lake has a relatively small watershed to lake ratio of 8 to 1, with much of the watershed being comprised of agricultural lands. Eight species of fish were sampled during the survey which should be considered a pretty simplistic low diversity lake. Rock Lake is managed primarily for Walleye and secondarily for Yellow Perch and Black Crappie. A standard survey was conducted the week of July 11, 2022 to monitor fish populations using three gill nets and nine trap nets. Walleye catch rates in Rock Lake have ranged from 6.0 per gill net in 2018 to 30.8 per gill net in 1987 and have averaged 16.1 per gill net since 1985. Prior to 2010, it was common to have catch rates higher than 17.5 per gill net (6 out of 7 surveys). In the recent three nettings before this survey, catch rates have been below 6.3 per gill net. In 2022, the catch rate of Walleye increased to 9.3 per gill net, which is within the expected range of catch rates for similar lakes (2.3 to 18.1 per gill net). Gill net catch rates were expected to be higher because fall electrofishing catch rates of Walleye fingerlings were high in 2016 (574.7 per hour) and 2021 (277.3 per hour). It is possible that the gill net catch rate was lower than expected, because there was a dense algae bloom occurring during the survey, which increases the visibility of the net and is thereby avoided by the fish. Walleye lengths ranged from 7.3 to 28.9 inches and averaged 15.5 inches. The Walleye population in Rock Lake is stable, as six year classes of Walleye were sampled including Age-1, 2, 4, 5, 6, and 8 fish. The presence of Walleye from years where no stocking occurred is an indication that some limited natural reproduction occurs as the age-2 (N=1) and age-5 (N=2) Walleye were from non-stocked years. All other year classes sampled were from stocked years. The average length at age-1, age-4, and age-6 was 8.2 inches, 17.2 inches, and 20.5 inches, respectively, which are similar to average length at age estimates for other Walleye populations in similar lakes. Yellow Perch catch rates have ranged from 2.5 per gill net in 1985 to 33.7 per gill net in 2010 and have averaged 16.1 per gill net since 1985. In 2022, the Yellow Perch catch rate was 8.7 per gill net, which is within the expected range of catch rates for similar lakes (2.7 to 25.0 per gill net). Lengths of Yellow Perch ranged from 6.4 to 9.7 inches and averaged 8.7 inches. Yellow Perch are feeding successfully, as fish in the sample were plump. Black Crappie have historically occurred in low abundance in Rock Lake, with catch rates being near the lower end of the expected range of catch rates for similar lakes (1.2 per trap net) since surveys began in 1985. The 2022 catch rate remained low at 3.2 per trap net. Black Crappie lengths ranged from 4.4 to 12.8 inches and averaged 9.7 inches. Although abundance was relatively low, 65 percent of the Black Crappie sampled were 10.0 inches or larger. Channel Catfish were first sampled in Rock Lake in 2014 and Bigmouth Buffalo in 2018. In 2022, the Bigmouth Buffalo catch rate was 1.7 per gill net and zero Channel Catfish were sampled. Black Bullhead abundance remained very low at 0.8 per trap net. Other species sampled included Common Carp, Orangespotted Sunfish, and White Sucker.

Rock Lake is a 439-acre, class 43 lake, located approximately 3 miles south of the City of Russell in Lyon County. Rock Lake is managed primarily for Walleye and secondarily for Yellow Perch and Black Crappie. Lower Mississippi Strain Walleye were stocked in Rock Lake in 2016, 2018, and 2021. Walleye were not stocked in 2020 because of the COVID-19 pandemic, so Walleye were stocked in 2021 despite being an "off" year. A Walleye fry stocking evaluation using daytime electrofishing was conducted on September 21, 2021 to determine if the abundance of Age 0 Walleye. Young-of-the-year (YOY) Walleye were captured at a rate of 277.3 per hour, which indicates that the fry stocking was successful or natural reproduction occurred in Rock Lake. Walleye fingerlings were 4.3 to 7.0 inches in length and averaged 5.4 inches. Assuming survival to Spring of 2022 of the Fall Age 0 Walleye in Rock Lake, the 2021 year class should be a strong year class in the Rock Lake Walleye population.

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

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

Rock has a maximum depth of 7.9 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Rock is from 2022.

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