Poplar Creek has no individual Region 4 regulation entry. It sits on the Lardeau side of the Duncan/Lardeau country, where the regional table sets Lardeau River mainstem rules and Trout Lake's tributaries to bull trout catch-and-release, but neither bucket is confirmed for Poplar Creek specifically. The regional default stream rules apply regardless: no fishing April 1 to June 14, trout and char release in streams November 1 to March 31, and single barbless hooks required. Confirm the current synopsis or call the Region 4 office before fishing.

Poplar Creek carries an official provincial name in the Kootenay Land District (NRCan key JBCXF), cited at 50.415556, -117.121389. A nearby locality shares the name, but this page covers the creek 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) and stretches roughly 25 km through Lardeau country. The 2013 Kootenay Lake bull trout redd survey describes Poplar Creek as a Lardeau River tributary, and found a complete natural barrier around 4.4 km upstream with 4.24 km of accessible adfluvial spawning habitat below it. One Upper Duncan bull trout monitoring report notes that juvenile Poplar Creek samples were unavailable for its otolith analysis, so the creek sits outside that particular data set even though it is part of the same monitored system. Goat Range Park planning material places the upper creek in wilderness and conservation zoning, and flags uncertainty around the Poplar Creek Road that provides access.

With only two confirmed fish records, no guide coverage and no public fishing reports, Poplar Creek is not a destination to plan a trip around. Its real significance is the 2013 spawner survey: 23 complete redds and 11 adult bull trout counted in the accessible reach below the barrier, a genuine and fairly productive spawning run for a creek this size. That makes it spawning-system water first. Do not target redds, staging adults or fish holding in low, warm late-summer flows, and treat any bull trout encountered here the same way anglers treat other confirmed Duncan/Lardeau spawning tributaries such as East Creek.

Poplar Creek has no dedicated hatch survey. Its likely food base follows the pattern of other cold Lardeau bull trout tributaries: small fish, kokanee during their run, juvenile trout and char, and sculpin for the resident predators, with a lighter trout-food layer of small mayflies, caddisflies, stoneflies and terrestrials. No fly recommendation is offered here until the legal status is confirmed; if a legal, non-spawning-season opportunity is verified, small streamers, general nymphs such as a Hare's Ear or Pheasant Tail, and attractor dries like a Stimulator or Adams would be the starting point, fished well away from any visible bull trout.

No named trailhead, parking area or public access point has been confirmed for Poplar Creek. Goat Range Park planning material flags the Poplar Creek Road as an uncertain access route into the upper wilderness-zoned reach, so confirm current road and park status before making a trip of it. Until access and the regulation bucket are both confirmed, treat this as a regulation-and-access check water rather than an assumed open fishery.