Slate

Slate Lake is a shallow lake with bog colored water that is connected to the Stony River and located about fifteen miles northwest of Isabella in the Superior National Forest. There is an earthen boat ramp off State Highway 1 located on recently acquired DNR land that, as of 2024, is not a designated and maintained facility but does provide public access. Boaters should use caution when navigating around the lake because large boulders and shallow rocky areas occur throughout the lake which can damage boat motors if contacted. The Walleye catch rate of 3.17 per gill net was within the normal range for similar lakes in the area and within the range of catches from seven previous surveys of Slate Lake. The size structure of the catch was poor with few fish longer than 15 inches sampled, which is consistent with historic survey data. Age analysis documented successful natural reproduction from each of the past five years indicating anglers should continue to have similar opportunities to catch and harvest smaller sized Walleye into the future. The Northern Pike population also has average abundance and small size structure with documented natural reproduction from each of the past six years. The 2024 survey confirmed the trend from historic surveys that few pike reach trophy size, but decent numbers of modest sized fish are available to anglers. Bluegill are also present and have been sampled in low numbers during standard fisheries assessments since first being sampled in the lake in 1999. While only a few adult Bluegill were captured in 2024, targeted spring trap netting surveys completed in 2019 and 2022 sampled more fish and provide additional information about the status of the population. A small number of Smallmouth Bass were again captured in 2024 continuing a trend of low catches since the species was first sampled in the lake in 2005. These results are similar to other connected waterbodies in the area that support a small population of bass that can survive for many years and grow to decent sizes. Anglers may have difficulty targeting the species due to the low density of the population. White Sucker and Yellow Perch are important forage species and were caught in normal numbers compared to similar lakes in the area. Some incidental harvest may occur but neither species is likely to be targeted by anglers using hook and line.

Slate Lake is a 293 acre lake with a maximum depth of seven feet located along State Highway 1 northwest of Isabella. The Stony River flows through the lake and access is gained via the river channel below the lake outlet. Anglers then paddle or motor upstream from the access into the lake. There are many rocks that are difficult to see in the dark water and a shallow rocky riffle between the access and the lake that can be hazardous to motor boats. Spring trap netting was completed on Slate Lake during early June of 2022 to gather information on the Bluegill population that was first detected in the lake in 1999. A total of 89 Bluegill were sampled, almost twice as many as sampled in the 2019 survey, and a good number for this area. Size structure remained good with 56 percent of the sample longer than eight inches and the longest fish measuring over 11 inches. Bluegill ranged from two to eight years old with each year class represented indicating consistent reproduction in recent years. The population will continue to be monitored because the lake is one of only a few in the Finland Area that supports a fishable Bluegill population with opportunities for anglers to potentially catch a memorable fish. Slate Lake has a diverse fish community with a variety of sportfish populations available to anglers. Walleye, Northern Pike, Smallmouth Bass, Pumpkinseed Sunfish, Rock Bass, White Sucker, and Yellow Perch were also sampled during this survey.

A targeted survey for Bluegill was carried out on Slate Lake the week of June 3rd 2019 when water temperatures were around 60 degrees Fahrenheit. The purpose of this survey was to assess the current state of the Bluegill population in the lake and to establish baseline data to work from into the future. During the survey, a total of 49 Bluegill were sampled. These fish had an average length of 8 inches and a maximum length of approximately 10.5 inches; 53 percent of the sampled Bluegill were 8 inches or longer. Ages ranged from four to 10 years old with growth rates near average when compared to other area Bluegill populations. Slate Lake supports a fishable Bluegill population with good growth, consistent enough recruitment that the population is expected to persist into the future, and opportunities for anglers to catch large fish. Slate Lake is primarily managed for Walleye with a secondary fishery for Northern Pike. A total of 15 Walleye were sampled in the survey with an average length of just under 14 inches. Northern Pike were sampled in large numbers (72 total sampled) with an average length of 17.5 inches. Golden Shiner, Pumpkinseed, Rock Bass, Smallmouth Bass, White Sucker, and Yellow Perch were also sampled during this survey.

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

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

Slate has a maximum depth of 7 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Slate is from 2024.

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