Dewar Creek runs down out of the Purcell Wilderness Conservancy backcountry to join the St. Mary River above Kimberley. It is one of three known primary bull trout spawning tributaries in the upper St. Mary system: the Freshwater Fisheries Society of BC lists it alongside White Creek and Redding Creek, and provincial records show a strong westslope cutthroat and bull trout signal through its length. That conservation value, not casual fishing pressure, is Dewar's defining character.
The water
NRCan's Geographical Names database lists Dewar Creek as an official Kootenay Land District name at 49.703611, -116.373611. It runs stream order 6 (high on the network, on a scale that runs from 1 for a headwater trickle up to 6 or more for a full river), stretches roughly 43 km, and drains into the St. Mary River near Marysville. Two named tributaries carry their own direct fish records: White Creek, the larger order-5 child stream, and Coppery Creek, a small side drainage further upstream. A 2009 fish-passage assessment of a second-order Dewar side-tributary (project SMAR-D01) describes the Dewar mainstem itself as a fifth-order St. Mary tributary known from provincial data for westslope cutthroat trout, bull trout and mountain whitefish; the assessed side-tributary had steep, poor-diversity habitat, temporary debris barriers, and no recommended passage improvement.
The fishing
Provincial fish-inventory data lists 69 direct observations on Dewar Creek: 34 westslope cutthroat trout, 11 bull trout, 8 Dolly Varden, 7 mountain whitefish, 7 sculpin (5 slimy, 2 unidentified) and 2 Burbot. That is a genuine native trout-and-char signal, not proof of a developed fishery: no public trailhead, parking area or put-in specific to fishing Dewar Creek has been confirmed, and the creek's role as one of three known primary bull trout spawning streams in the upper St. Mary system means late-season staging fish and redds should be left alone entirely.
Use the upper St. Mary / East Kootenay food base until direct Dewar samples exist: Stoneflies near the opener, Mayflies, Caddisflies (Sedges), summer Terrestrials (Hoppers, Ants, Beetles), midges, fry and Sculpin. Where fishing is legal and away from spawning fish, a small-stream kit built on Stimulators, Chubby Chernobyls, Royal Wulffs, Adams, PMXs and Elk Hair Caddis on top, with Pat's Rubber Legs, Prince, Hare's Ear, Pheasant Tail and Copper John nymphs underneath, covers the water. Bull trout anglers use a sparse Woolly Bugger or Muddler Minnow only where legal and only well away from spawning activity; this reads first as small-stream dry-fly water for cutthroat, not streamer water for char.
No Dewar-specific guide coverage has been found. St. Mary Angler, Elk River Guiding Company and Kimberley Fly Fishing all guide the St. Mary River mainstem and can speak to regional conditions, but that is context, not an endorsement to fish this particular tributary.
A spawning stream first, a fishery second
Conditions
- Navigability: the channel-geometry numbers (median width ~19.7 m, moderate to wide; gradient ~1.12%, gentle; peak mean-annual discharge ~8.715 m³/s, moderate flow) describe a mainstem-scale tributary, though the barrier and habitat findings on its own side-tributaries show plenty of steep, broken water higher in the system.
- Stocking: no stocking record. Dewar runs entirely on wild, self-sustaining cutthroat and char, which is exactly why its spawning role matters.
Access and the rules
BC Parks accesses the east side of the Purcell Wilderness Conservancy by gravel roads along the St. Mary River and Dewar Creek, warning of industrial logging traffic and a non-mechanized park boundary beyond the road end. The Dewar Creek Hot Springs trail starts from the West Fork St. Mary junction; the final few kilometres are rough, and BC Parks recommends a high-clearance vehicle. No named public trailhead, parking area or put-in specific to fishing Dewar Creek itself has been confirmed, so treat any approach as backcountry travel.


