Blackduck Lake is a 2,596-acre lake with a maximum depth of 28 feet. The lake is located 1 mile west of the city of Blackduck in Beltrami County. There is a DNR public water access located on the eastern shore of the lake off of County Road 30. Several resorts and a modest number of lake homes dot the shoreline. A special regulation consisting of a 5-fish bag limit for sunfish was implemented in 2006. Statewide regulations apply to all other species.
The walleye population of Blackduck Lake is maintained by fry stocking, which has been a successful management tool in producing consistent walleye fishing. The 2012 walleye catch rate (9.7 fish/gill net) marks the third consecutive assessment with catch rates better than the statewide upper quartile value of 8.8 fish/gill net for class 27 lakes. Walleye grow quickly in Blackduck Lake, usually reaching 14 inches in length sometime during their fourth growing season (age 3+). Angler harvest rates of walleye tend to be high as well, resulting in a fish population usually dominated by younger fish with lots of "eaters" produced each year. Walleye captured in the 2012 fish population assessment averaged 13.8 inches and 1.08 pounds, with fish up to 28.9 inches in length present in the sample. Walleye from the abundant 2011 year class (age-1 fish) comprised a large proportion of the sample (24%), and these fish should reach harvestable sizes by 2014. Blackduck Lake is especially popular with walleye anglers from the May fishing opener through mid-summer.
Blackduck Lake also provides good fishing opportunities for sunfish (bluegill and pumpkinseed), northern pike, and yellow perch. The lake has shown the potential to produce large bluegill in the past, and in 2006 a special sunfish regulation (5-fish bag limit) was implemented to maintain the quality size structure that was present at that time; however, in the 2012 assessment, bluegill were captured in very low numbers. The 2012 northern pike catch rate of 7.8 fish/gill net approaches the statewide third quartile value of 9.0 fish/gill net which is within the normal range for class 27 lakes. Northern pike had an average length and weight of 22.3 inches and 2.41 pounds, with fish up to 33.3 inches in length present in the sample. Yellow perch are an important forage species as well as being a popular target for anglers. The 2012 population assessment showed a decline in both perch numbers and size since the 2006 assessment, although fish up to 12 inches in length were still present in the sample. Black crappie abundance in Blackduck Lake is relatively low, but with some large individuals (greater than 12 inches in length) present in the population.