Fishing Lake Fifteen

Lake Fifteen is dominated by northern pike that make trout survival extremely difficult, explaining why DNR stopped stocking in 2019 after nearly 50 years of poor returns. The lake's extremely oligotrophic conditions with chlorophyll-a at just 0.00131 mg/L mean limited productivity and small panfish — rock bass, bluegill, and yellow perch all grew below state average and most were under 6 inches. Northern pike historically made up 20-23% of survey catches and likely controlled the fishery, though only 3 were captured in the 2011 survey. Brown trout showed excellent growth at +1.3 above state average, but most large trout are likely emigrants from heavily-stocked McCormick Lake upstream via the Thunder Bay River connection. The lake's steep drop-offs and narrow littoral zone concentrate fish in limited habitat, with good dissolved oxygen down to 30 feet during summer stratification. Rainbow smelt support a popular winter fishery despite periodic die-offs in 1953 and 2002; this non-native species replaced the native cisco population sometime after the 1940s introduction. Largemouth bass showed above-average growth at +0.4, likely benefiting from abundant small prey fish, with 44% exceeding the 14-inch size limit. The lake's sand, marl, and gravel bottom provides clean substrate, and the strong summer thermocline with surface temperatures of 71°F dropping to 42°F at 55 feet creates distinct thermal layers. With high alkalinity at 200 mg/L but extremely low nutrients, this two-story lake offers summer fishing for largemouth bass and panfish plus specialized winter smelt fishing, though overall fishing quality remains low due to the sterile, unproductive conditions.