I haven't been there for about 10 years now, but several decades ago my friends and I discovered a gem of a trout stream while camping just off a highway on Vancouver Island. We chose a scenic site along a medium sized coastal river, and tried our luck casting various lures into several deep pools. Lots of small trout took the challenge, but nothing substantial. Sensing the unlikelihood of bigger fish, we decided to forego fishing, and instead forage for wildberries to augment our breakfast pancakes. In the pursuit of huckleberries, salmonberries, and thimbleberries, we stumbled on a small stream emanating from a narrow canyon. Walking along the top of the canyon, we continued upstream in search of more berries while enjoying the incredible scenery below. After about 60 minutes of bushwacking, we came to the head of the canyon, with a waterfall cascading into big pool about 20m below. We decided to rest a bit, and to take in the natural beauty. Being a warm late summer, we soon started looking for ways down into the canyon to enjoy a dip in the cooling waters.
While carefully studying the canyon for a safe way down, I happened to notice some motion in the small stream exiting from the pool. It seemed we had spooked a nice sized trout, and it had decided to bid a hasty retreat from the stream back into the safety of the deeper pool. Suddenly, we had a renewed interest in fishing! We drew sticks, and my buddy was tasked to go back to camp for some lightweight fishing gear, while I was left to map out a way down (and back up again).
By the time my buddy had returned, I had discovered out a safe traverse down to the stream and back again. With gear in hand, we made a couple short casts downstream from the pool, but had no takers. We then moved upstream in stealth mode to test the deep pool waters. My first cast across the to the base of the waterfall was almost immediately attacked by a fish too big for my 5' travel rod. After a short, but vigorous fight, I landed a nice fat 16" wild rainbow. Not to be outdone, my buddy also landed a similar nice fish. The next 2 or 3 casts each stimulated some nice fish, and every fish put up up a massive fight. Then, it suddenly stopped. For the next hour or so, nothing. We figured that the fish were on to us, and no longer wanted to play that game.
Getting cold (no sun reached the bottom of the canyon), we decided to call it a successful day, and vowed to return again in the morning. Which we did, and each managed to catch one more nice fish before they again wised up. We left the area the next day, but I returned almost every year to the same spot for several years until I left the Island for a career move. A couple decades later I returned with my 10 yr old son to show him the joy of wild trout. And the trout were still there, still easily spooked, and self limiting catches of nice rainbows.
I have never confirmed it, but I think that the unnamed creek must have been a natural steelhead nursery. High water flows in the fall would allow fish to escape the small stream in favour of the salt chuck, while continued flows would allow winter spawners back into the system. Frys hatched in the stream would fatten up in the pool below the falls, but then stay there as the low summer water flows restricted downstream migration. I don't know how long the fish would remain resident in the stream, but I understood that almost all rainbows in the coastal Island streams are migratory, hence "steelhead" and would eventually seek the salt chuck when big enough (12 ~ 16"?).
I still dream of that pristine place, or of finding another similar gem closer to my current home.