Fishing O'Sullivan Lake in Thunder Bay District, Ontario

• Overview

  Thunder Bay District in Ontario is where O'Sullivan Lake sits. The water sits 293 metres up. At roughly 45.31 sq km it ranks among the larger waters in the region. The bank runs about 180 km in total, split between open shore and sheltered corners. Size puts it in the front rank of our Thunder Bay District list. Start from Greenstone, 77 km down the road. For a city, Thunder Bay is 277 km off. One jurisdiction covers this water end to end.

• Where to Fish on O'Sullivan Lake

  No chart reached our records; the first cast is your sounding. A natural lake fishes on cover, and cover here means weed and timber. Look for the band where the shallows give up and the bottom falls away. Survey and observation records for Thunder Bay District include cisco, blackfin cisco and rainbow smelt. Those are county-wide records, so not every one of them will be in this water. Treat O'Sullivan Lake as a water to read rather than to cover.

• Seasonal Patterns

  On the long-term average, July reads 16°C and January reads -20°C. Little of the calendar is open water, so timing counts for everything. Expect a solid lid for months and a thaw around early May. Averages place the thaw at early May and the freeze at mid November. The middle of summer slows a little, with dawn and dusk carrying it. O'Sullivan Lake fishes to that pattern most years.

• Tackle & Baits

  The rules here are undocumented as far as public sources go. This is a natural basin, not a dammed one. Nothing is mapped in the way of a ramp or car park within a short radius. One rod, a handful of hooks and floats, and a few small lures are enough for this water. Parking is often the real limit rather than the bank itself. Access can change hands, so last year's answer may not hold. Hurd Lake, 5.3 km away, makes the obvious fallback. Nothing on O'Sullivan Lake should be assumed from this page alone.