Portage

A targeted survey of nearshore fish species in Portage Lake was conducted on June 16, 2025, by Lake Biological Monitoring and Assessment (LBMA) Program 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 10 sampling stations. Similarly, a 50-foot seine was used at all stations. Nearshore sampling captured 17 species of fish including five species that are intolerant of disturbance (i.e., Banded Killifish, Blackchin Shiner, Blacknose Shiner, Iowa Darter, and Rock Bass) and none that are tolerant of disturbance. A summer trap net survey was conducted by LBMA Program staff during the week of June 16, 2025. Nine trap nets were set along the shoreline in locations that encompassed multiple habitat types. Trap net sampling captured twelve species of fish, including one that is intolerant of disturbance (i.e., Rock Bass) and one that is tolerant of disturbance (i.e., Black Bullhead). Bluegill comprised a majority of the catch by number and whereas Bowfin comprised a majority by biomass. The nearshore and trap net survey data were combined with gill net data from a survey conducted during the week of June 12, 2023 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., Black Bullhead). 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. Results from this survey provide evidence that the fish community Portage Lake is healthy as indicated by an FIBI score that meets the exceptional aquatic life use threshold determined for similar lakes. The FIBI results are similar to previous findings, which indicated that Portage Lake is fully supporting aquatic life use. The survey results will be considered when the biological health of the lake is assessed during the Mississippi River-Brainerd Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency. You can help protect the fish community in Portage Lake by reducing runoff, maintaining natural shorelines, and preventing the spread of invasive species.

A targeted survey of nearshore fish species in Portage Lake was conducted on July 12, 2023, by Index of Biological Integrity (IBI) Program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot seine. Nearshore sampling captured twenty-three species of fish including eight species that are intolerant of disturbance (i.e., Banded Killifish, Blackchin Shiner, Blacknose Shiner, Iowa Darter, Least Darter, Mimic Shiner, Rock Bass, and Smallmouth Bass) and two that are tolerant of disturbance (i.e., Black Bullhead and Fathead Minnow). The nearshore data were combined with trap net and gill net data from a June 2023 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., Black Bullhead and Fathead Minnow). 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. Results from this survey provide evidence that the fish community in Portage Lake is healthy as indicated by an FIBI score that exceeds the exceptional use threshold determined for similar lakes. These results are similar to previous survey findings, which indicated that Portage Lake fully supported aquatic life use based on the FIBI. The survey results will be considered when the biological health of the lake is assessed during the Mississippi River - Brainerd Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency.

Access to Portage Lake is possible by launching at the Public Access at Crooked Lake and then taking channels to Hanks and then finally Portage. Water was especially low in 2023 due to the drought conditions and made access into Portage Lake difficult to impossible by the end of the summer for many boats. Northern Pike were present in high numbers (12.8/gill net). Size, however, may be more of an issue for those hoping to target this species. While fish up to 34.4" were present, the average size of 20.9" left a lot to be desired. Similar was true for Largemouth bass. An electrofishing catch rate of 196.5/hour more than tripled the previous survey's catch (64/hour), but average size was only 10.7". The largest fish measured was 16.7". Walleyes have been stocked by the Lake Association since 2008 and while numbers weren't particularly high in 2023 at 1.7/gill net, this was still average for this type of lake and could offer some fishing opportunities. Most of the fish were large, with an average length of 20.4" and all the fish measuring 12" or larger. The panfish population didn't offer much for anglers to be excited about. Black Crappie numbers were low at 0.3/gill net and the largest fish caught was 8.9". Bluegill numbers were a little better at 9.1/trap net, but only 12% of the fish were larger than 7". Tullibee (Cisco) were sampled in high numbers at 18.3/gill net and had an average length of 11.8". Tullibee (Cisco) are an important forage fish for larger Northern Pike and Walleyes; they can also provide a unique fishing opportunity. With most Tullibee (Cisco) fishing done through the ice, it may be difficult to target this population due to there being no direct winter access on Portage Lake. Eurasian Watermilfoil is present in this chain of lakes. Before and after launching lake users are required to inspect and remove any aquatic plants and animals from their watercraft and trailers as well as pull the plug and drain all water from the watercraft, including bilges, livewells and baitwells.

Based on Minnesota DNR survey data, anglers target Largemouth Bass, Hybrid Sunfish, Walleye, Bluegill, and Yellow Perch in Portage. See the full species list above for catch rates, size structure, and quality scores.

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

Portage has a maximum depth of 37 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Portage is from 2025.

Yes — Portage has confirmed Eurasian watermilfoil. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.