Acreage: 129 acWater clarity - 5.5 ft - stainedStocking: stocking-related note present - Narrative: Boulder is a 3,882-acre reservoir located 12 miles north of Duluth, MN. Boulder has a developed, state administered, public access located near the dam on the southern tip of the west basin at the terminus of the Boulder Dam Road. Maximum depth is 18 feet with 85% of the lake shallower than 15 feet. Boulder is operated as a water storage reservoir by Minnesota Power and is subject to water level manipulation. Shoreline development on the lake is limited, and watercraft travel can be dangerous as all underwater navigational hazards are unmarked. Boulder was assessed during the summer of 2023 to update information about fish populations. Walleye have not been stocked into Boulder since 1991 because sufficient natural reproduction has been documented to sustain the walleye fishery. Walleye abundance of 6.7 per gillnet lift was average compared to other similar Minnesota lakes. Average length was 14.3 inches but Walleye up to 25.0 inches long were sampled. Walleye angling on Boulder should be very good in 2024 and beyond with several strong year-class and very consistent recruitment. Black Crappie population densities were average compared to other similar Minnesota lakes. Black Crappie mean length was large at 10.5 inches, and growth was fast when compared to other Duluth Area lakes. Sample size was small but one-third of the overall catch exceeded 12 inches in length. Yellow Perch abundance of 4.3 per gillnet lift was below average compared to other similar Minnesota lakes. Average length was 8.3 inches and 28% of the fish captured exceeded 10 inches in length. Northern Pike abundance of 2.6 per gillnet lift was average compared to other Minnesota lakes, but average length was small at 18.9 inches. Other fish species sampled included Black Bullhead, Burbot, Golden Shiner, Pumpkinseed Sunfish, Rock Bass and White Sucker.