Fosthall Creek is an official Kootenay Land District creek that drains the Monashee Mountains into Upper Arrow Lake, part of the Columbia River system, on the lake's west shore north of Nakusp. Provincial fish-inventory data gives it a direct rainbow trout and sculpin record, stronger footing than a pure connectivity guess, though the creek is still mostly a regulation-and-access check rather than a known destination.
The water
NRCan/GeoGratis places the creek's mouth at 50.360833, -117.9425 (key JAGQV), on Upper Arrow Lake at Fosthall Bay, roughly 14-16 km north of Nakusp along the same shore. A second, separate water, South Fosthall Creek (key JBKVZ), enters the lake a little further south near 50.369, -118.034 and carries its own, stronger fish-record history; don't confuse the two when reading local maps or older reports. Fosthall Creek itself runs stream order 5 (mid-range toward river scale on the 1-to-6+ network used across this vault) for roughly 32 km before reaching the lake.
Provincial fish-inventory data directly confirms rainbow trout and sculpin in Fosthall Creek. Bull trout and westslope cutthroat are reachable habitat under barrier-aware connectivity modelling, and dolly varden also shows up in the broader habitat read for this drainage, though none of the three has a direct record on file yet (no dedicated species page exists for dolly varden either).
The fishing
Above the bay, fish it like a small Monashee-side tributary: short drifts with a buoyant dry over a light dropper through the pocket water and pool heads, the same small-stream dry-fly approach that works across the region's cutthroat creeks. At the mouth itself, rainbow trout and any staging char will sit off the creek's plume where cooler, oxygenated water meets the lake, worth a few casts from a boat before heading up the trail.
No hatch report specific to Fosthall Creek has turned up. Until one does, fish the general moving-water calendar mined from the wider East Kootenay corridor as a starting point rather than a confirmed local hatch: golden stoneflies into early summer, summer mayflies, caddis from mid-June, and terrestrials as the water drops in August. Start with a Stimulator, small Chubby Chernobyl or Royal Wulff, switch to an Adams or Elk Hair Caddis as fish get selective, and carry Hare's Ear and Pheasant Tail nymphs for the pocket water. The confirmed sculpin record backs up a small Woolly Bugger or Muddler Minnow for any bull trout working the creek mouth.
Bull trout: handle with care
Health and stewardship
No dedicated habitat or water-quality survey specific to Fosthall Creek has turned up. Treat the drainage with the same care as any Monashee-side spawning tributary: keep to established trails near the bay, and avoid disturbing spawning gravel if you fish the creek mouth in season.
Conditions
- Navigability: no bcfishpass channel-geometry record exists for Fosthall Creek. Treat it as a small walk-in tributary above the bay, not driftable water.
- Stocking: no stocking record. It runs on wild fish.
Access and the rules
Fosthall Bay itself is boat-in only, roughly 14-16 km up Upper Arrow Lake's west shore from Nakusp; there's no drive-in road to the bay. A recreation site with informal camping sits close to the creek, and a short trail climbs from the bay to Fosthall Falls. Whether a Forest Service Road reaches the bay from inland, or only serves the upper drainage, isn't confirmed. No guide coverage specific to Fosthall Creek was found.
