Portage

Portage Lake is 372 acres with an average depth of 8 feet and a maximum depth of 18 feet. A targeted panfish assessment was conducted on 5/14/2025. A total of 34 Bluegill were captured for a trap net catch rate of 5.7 per net. Bluegill averaged 6.7 inches with fish up to 9.3 inches observed. Fish ranged from 2 to 8 years old with age 7 (2018 year-class) fish absent in the sample. Ages 4 and 5 (2021 and 2020 year-class) were the most frequent age-classes in the sample and made up 32 and 44 percent of the Bluegill catch. Bluegill averaged 6.2 inches in 4 years and was within the range of previous assessments (historical range was 3.9 to 7.2 inches at age 4). Thirty-seven Black Crappie were sampled, resulting in a trap net catch rate of 6.1 per net. Crappie averaged 9.2 inches with fish up to 14.0 inches observed. Fish ranged from 4 to 9 years old with all age-classes observed. Age 5 (2020 year-class) fish were the most frequent in the sample and accounted for 35 percent of the Crappie catch. Crappie averaged 7.3 inches in 4 years and was within the range of previous assessments (Historic range was 5.5 to 7.5 inches at age 4).

This survey was conducted on 2/27/2025 to gauge the likelihood of a winterkill occurring on Portage Lake. Winter dissolved oxygen levels were good for Portage Lake and likely tolerable based on this survey with 4.5 ppm below the ice and 1.1 ppm near the bottom. Therefore, it seemed unlikely for any significant winterkill to occur in spring 2025.

A targeted survey of nearshore fish species in Portage Lake was conducted on August 8, 2022 by Aitkin Area Fisheries 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 all ten sampling stations, but three stations were sampled from the boat due to site conditions. Similarly, a 50-foot seine was used to sample five stations, a 15-foot seine was used at one station, and site conditions prevented the use of seines at four stations. Four site locations had to be moved slightly to allow the minimum amount of seine hauls necessary for sampling. Nearshore sampling captured eleven species of fish including one species that was intolerant of disturbance (Iowa Darter) and one that was tolerant of disturbance (Black Bullhead). The nearshore data was combined with trap net and gill net data from a June 2022 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., Fathead Minnow and Green Sunfish). 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 website. Data from this survey indicates the fish community of Portage Lake is in good health as indicated by an FIBI score above the impairment threshold for aquatic life use determined for similar lakes. Data from this survey will contribute biological information about the health of the fish community to the Mississippi River-Grand Rapids Watershed assessment process in coordination with MN Pollution Control Agency.

Based on Minnesota DNR survey data, anglers target Northern Pike, Black Crappie, Bluegill, Yellow Perch, and Pumpkinseed in Portage. See the full species list above for catch rates, size structure, and quality scores.

We don't have a confirmed public access point on record for Portage. Check the DNR LakeFinder page for current access details before you go.

Portage has a maximum depth of 18 feet and a mean depth of 8 feet, per Minnesota DNR data.

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

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