No Templeton River-specific exception appears in the Region 4 synopsis, so regional defaults apply: closed to fishing Apr 1 to Jun 14, trout and char catch-and-release from Nov 1 to Mar 31, and a single barbless hook required all year. Confirm the current synopsis and any in-season notices before fishing.

The Steamboat Mountain fish habitat inventory treats the Templeton system as glacier- and alpine-lake-fed, with plateau wetlands and lake outlets doing much of the rearing and spawning work rather than the open channel itself. It runs stream order 5 (well down the network toward river scale, on a system that runs from 1 for a headwater trickle up to 6 or more for a full river) across 112 mapped segments, with a median channel width around 7.1 m (narrow to moderate) and a gradient around 2.15% (moderate), consistent with a cold mountain river rather than a broad valley-bottom drift.

A falls in reach 4 blocks upstream migration from the Columbia, and a second falls at the Templeton Lake outlet blocks movement into the lake itself. Fish living above those barriers are better read as resident or lake- and tributary-connected populations rather than fresh runs up from the Columbia. The wider Columbia basin is a recognized priority area for at-risk aquatic species, with habitat loss, reduced water quality and quantity, barriers and invasive species named as the main basin-scale pressures, so the falls, lake outlets and wetlands that shape this river's fish movement are worth protecting on their own terms.

Start with compact dry/dropper and nymph water in the accessible, cool-flowing reaches rather than hunting for big holding water: the inventory notes that deep pools for larger adult fish are limited on these streams. Westslope cutthroat, rainbow trout and brook trout make up the local catch, tied to the lake-outlet and wetland habitat described above rather than easy roadside runs.

Fish it with a cold mountain-creek box: a Stimulator or Royal Wulff up top, an Elk Hair Caddis and Adams through summer hatches, then a Hare's Ear, Prince Nymph or Pheasant Tail with a small Woolly Bugger worked through the deeper pockets. Stoneflies, caddisflies, mayflies, summer terrestrials, small sculpin, baitfish and fry and trout fry round out the food base.

Reach the drainage from the Brisco crossing on Highway 95, north of Radium Hot Springs, then follow the tertiary logging-road network that also serves the Dunbar Creek, Cartwright, Botts, Twin, Halfway and Leadqueen lakes area. Regional back-country mapping marks these as active, radio-assisted logging roads, so treat every crossing as industrial ground first: never block a road, and confirm current conditions before heading in. Which reaches are fishable without crossing private or active industrial ground has not been confirmed. Kootenay Troutfitters is the nearest established Columbia Valley guide operation, though no source confirms dedicated Templeton River trips.