Portage

Portage Lake is a designated stream trout lake that has been managed for Splake since 1982. The lake is located near the mid-Gunflint Trail area, about 35 miles from the City of Grand Marais. The most direct public access to the lake is from a 0.10-mile portage trail from the east end of Iron Lake which connects with the northern arm of Portage Lake. The 2022 standard lake survey was the last of three scheduled in the current (2009) lake management plan to evaluate a shift to alternate-year Splake stocking that began in 2011. Goals for the population under the new stocking regime are to maintain a minimum Splake gill net catch of 10.0 fish/set, including the presence of two catchable-sized (over 10 inch) year classes in each survey. This was the second survey to sample a Splake population supported only by alternate-year stocking. Management goals for Splake were not met in this survey. Although the gill net catch fell below the abundance goal, it remained similar to past Splake catch rates observed when the lake was stocked on an annual basis. The 2022 sample was dominated by three-year-old Splake which averaged about 14 inches at the time of capture. Growth rates of age-3 fish were considered average for the area; the mean length at the end of their third year was 12.90 inches, compared to an area mean 12.6 inches at that age. The catch of age-1 Splake from the 2021 stocking was low; however, those fish averaged seven inches in length when sampled and may not have been fully susceptible to survey nets at that time. Survival of Splake beyond age-4 has appeared low in Portage Lake, and none of the Splake stocked in 2017 (age-5 in 2022) were captured in this survey. White Sucker and Green Sunfish are the primary undesirable fish species (for stream trout management) established in Portage Lake. Both species can compete with Splake for invertebrate forage, although Splake have been known to feed on small Green Sunfish. White Sucker have been abundant in most surveys of Portage Lake and the 2022 gill net catch suggested a similarly abundant population remained present. Green Sunfish abundance has appeared low in most gill net surveys of the lake, and only one fish was sampled in 2022.

Portage Lake has been managed for stream trout (Splake) since it was reclaimed for that purpose in 1982. This was the second of three surveys scheduled in the current (2009) lake management plan to evaluate a shift to alternate-year stocking that began as a cost-saving measure in 2011. This was the first of those surveys to sample a Splake population supported only by alternate-year stocking. Splake were apparently abundant in 2017, and their size was perhaps a bit above average, compared to Splake in other area lakes. Management goals for Splake in this lake were met in 2017. The gill net catch met the catch goal in the 2009 plan (a minimum of 10.0 fish/set), and two catchable-sized (over 10 inch) year classes contributed to that catch. Two stocked year classes (2015 and 2013) contributed to the catch, although it appeared that few fish remained from the 2013 stocking. Growth of young Splake had been average for the area; fish reached a mean length of 9.7 at the end of their second year. It was hoped that Splake growth (which had been slow) would improve under an alternate-year stocking regime, and results of the 2017 survey suggested that may have been the case. White Sucker apparently remained fairly abundant in 2017, with a gill net catch that was close to the average (6.50 fish/set) for spring catches in stream trout lakes in this area. Green Sunfish, which are also undesirable in a stream trout lake, remained present in 2017. Although the gill net catch was low, fairly high numbers were taken in minnow traps set as part of this survey. Both species compete with Splake for invertebrate forage. No new (to this lake) undesirable fish species were found in this survey. Minnow traps were used in this survey to better describe the nearshore fish community, which had never been sampled in this lake. Fathead Minnow and Finescale Dace taken in those traps provided additional forage for Splake, and were not considered undesirable in a stream trout lake.

Splake abundance in Portage Lake in the spring of 2010 was apparently low, both for this lake historically, and when compared to other stream trout lakes in the area. The splake gill net catch in 2010 fell short of the long range goal (10.0 fish/set) in the 2009 lake management plan. The goal from that plan of providing two catchable-sized year classes (fish over 10 inches) was barely met. No splake older than three years were collected. Most of the one-year-old fish from a 2009 fingerling stocking were probably too small to be taken in the sampling gear used in this assessment. Growth for two- and three-year-old splake collected had been slower than average. The white sucker gill net catch was well above the normal range for a lake of this class, and for a stream trout lake in this area. As high as the catch was, higher catches were observed in this lake in 2002 and 2005. Competition for invertebrate forage from this dense white sucker population is probably one factor limiting splake growth in this lake. Temperature-oxygen conditions suitable for splake (temperature under 65 F, oxygen over 5 ppm) were found at depths of about six to 42 ft on 6/2/2010. Conditions generally deteriorate as the summer progresses and surface waters warm, but in Portage Lake suitable conditions for splake could still be found at depths of about 15 to 21 ft on 8/19/2010. It is unlikely that summer water quality is a limiting factor for splake in this lake, at this time.

Based on Minnesota DNR survey data, anglers target Splake 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 55 feet and a mean depth of 17.8 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.